The mortality rate for those younger than 60 is between 6.8 percent and 13.2 percent, but jumps to between 43.3 percent and 55 percent for those 60 and older, the study found.
The research, led by Dr. Roy M. Anderson and Dr. Christl A. Donnelly, both of Imperial College in London, is to be reported in Saturday's issue of The Lancet, the British-based medical journal.
The current 10 day quarantine period used for those suspected of exposure to SARS may not be long enough.
The Lancet study, based on 1,425 SARS cases in Hong Kong up to April 28, also found that the maximum incubation period -- the time it takes between getting infected and becoming ill -- may be as long as 14 days.
Here is my advice for the day: Do Not Get SARS! Also, stay the heck away from China.
If China becomes a reservoir for Sars, other countries, particularly its neighbours, will have to maintain constant vigilance for cases arriving from the Far East.
Professor Tedder said it was possible that stringent surveillance precautions would be in place in the UK and Europe for the foreseeble future - and perhaps for years to come.
He said: "What it may prove to be is a very effective dry run - one wonders what will happen next time."
Given its mortality rate we really are lucky that SARS is not more easily transmittable. If the latest crossover of a virus from another species into humans had been an influenza with a lower mortality rate than SARS but still fairly high (say 2% like the 1918 Spanish Flu) it would not have been controlled in Western countries as easily. SARS ought to serve as a wake-up call for a future lethal virus that is more easily transmittable.
Then there is the continuing problem posed by SARS. It may become permanently established in China. If that is what is happening then it seems inevitable that sooner or later it will become established in the Indian subcontinent and Africa as well.
The World Health Organization has recently published a summary table of results of tests on how long the SARS virus can survive outside the body. The ability of the SARS virus to survive on a plastic surface at room temperature for at least 2 days provides key evidence for how SARS has been able to spread thru apartment buildings and hospitals.
Another experiment in Germany suggests that killing the SARS virus on surfaces is not a trivial matter.
German scientists found a common detergent failed to kill the virus, indicating that some efforts to sterilize contaminated areas may be ineffective. An experiment conducted in Japan concluded that the virus could live for extended periods in the cold, suggesting it could survive the winter.
On the bright side, the vast bulk of new SARS cases are happening in China and Hong Kong. But given the primitiveness of the health care system in much of China and the attempts of some probable SARS sufferers in China to avoid contact with authorities (poor Chinese people do not trust the government to care for them) it is likely that even if the Chinese government is honestly reporting all known SARS cases (by no means a certainty) there are probably cases in China that are going undetected. One should really take the WHO case numbers with a grain of salt for other reasons as well. The WHO's definition of what constititues a SARS case is narrower than the definition used by some national health authorities (notably the US CDC). India is reporting 20 SARS cases which India claims are confirmed by lab tests and yet WHO has no SARS cases listed for India. The number of SARS cases reported by WHO for the United States includes only the cases that the CDC lists as probable (and perhaps not even all of those? Or is WHO slow about updating counts?). The problem is that most people who have had a milder case of SARS do get listed as probable. Until reliable lab tests are widely used and accepted as definitive I expect WHO SARS case figures will continue to represent only a subset of all people infected by the virus.
On another brighter note, reports of relapsed SARS cases turn out to be unfounded.
HONG KONG -- A dozen former SARS patients here who were initially thought to have suffered relapses actually had other medical problems, health officials said Sunday, as the rate of new SARS cases being reported around the world slowed somewhat.
It is very unlikely that SARS will become established in Western industrial countries. Quarantines other public health measures can contain any new outbreaks that occur in large part because SARS is not too easily transmissible. However, as long as SARS is being passed around in China it threatens to make it into other less developed parts of the world.
A widespread lack of trust in their government is causing many Chinese people who suspect they are sick to avoid contact with doctors and hospitals.
"The government has said the people are panicking because they don't understand SARS, but that's wrong," said Kang, the social scientist. "They are panicking because they don't know who to rely on. The migrant workers in Beijing are afraid that if they are quarantined they won't get treated, just left there to get sick and die. Their flight is actually a rational response."
The previous report is more important than the fact that the WHO reports that SARS is declining in many of its major sites of infection.
BEIJING -As the World Health Organization announced that SARS had peaked and is declining in Hong Kong, Singapore and Canada, Chinese officials continue to withhold information crucial to combating the spread of the deadly virus, the U.N. agency's chief representative in Beijing charged Monday.
While some stock markets are rallying in reaction to WHO statements that SARS has peaked in many locations and a lot of people are breathing sighs of relief that perhaps the worst is behind us these optimistic reactions seem premature. SARS is being controlled in highly industrialized countries and also in Vietnam. But it is spreading deeper into China and there are worrying signs that it is getting a hold in India. With a 10th SARS case reported India has been reporting at least one SARS case a day for the last 4 to 5 days.
Medical experts warned that health authorities needed to do more to tackle the disease as SARS had entered the "local transmission" phase in which Indians who had returned to the country carrying the virus were now infecting fellow citizens.
If SARS becomes well established in rural India and rural China then there is no way it is going to be eradicated in the foreseeable future. There will then be a continuing risk that it will spread to still other less developed countries. An increasing portion of the world will come to be seen as made up of high risk destinations to visit. This will cut economic growth in those areas and in the world as a whole.
Individual Westerners who do not travel to regions which have SARS infection are going to continue to be at very low risk of getting the disease. In any locale where SARS shows up in the West the Western governments will conduct fairly aggressive programs to hospitalize sufferers and quarantine those who have been exposed (my guess is that other Western governments are learnng from Toronto to move quickly). The skilled personnel, supplies, and infrastructure are available to stop a local outbreak from getting out of control. Realistically a typical Westerner or resident of other industrialized countries such as Japan will be at greater risk of death from a car accident.
However, the economic impact of SARS is going to be great for the West in part because risk avoidance behaviors in the infected regions and among those who might otherwise travel to the infected regions will be so great. China is going to shut down its stock markets for at least a week. The economic effects of SARS are extending far beyond the infected countries and the global economy is slowing.
There are two big unknowns at this point:
Obviously, the answer to the first question greatly affects the size of the needed economic restructuring. But there are already many signs that computer and communications technologies are being used to reduce the economic impact of SARS. For instance, home banking use is surging in Hong Kong. Also, Video conferencing is enjoying a boom. Teleconferencing, telecommuting, email, mail order shopping, and other means of reducing one's exposure to other people are all helping to reduce the impact of SARS on the world economy.
The researchers discovered the two distinct patterns of disease. The five teenage patients had symptoms similar to SARS in adults - muscle pains, malaise, chill and rigour. However, the younger children had mainly coughs and runny noses with no muscle pains or chills.
And there is another more ironic proof of the seriousness of the situation — It is dusk here right now, and it is a clear, blue, glorious evening. The quality of this sky you do not see except when someone is in town that the government wants to impress, such as the International Olympic Committee, and the government shuts down the main thoroughfares and any industry that is going to pollute.
Air flights are not a huge source of risk for SARS infections. Aircraft use high-efficiency particulate air (HEPA) filters and take all bacteria and viruses out of the air at a very fast rate. Airplanes have better air filtering than commercial buildings.
Plane air is completely replaced with air from outside the aircraft 20 to 30 times every hour. This compares favourably against one to three times an hour in a typical building and five to seven times in a hospital operating theatre.
Granted, one could be seated on an aircraft right next to someone who has Severe Acute Respiratory Syndrome (SARS) and that person could cough on you. But consider the odds. The vast majority of those who have SARS are on the ground at any given time. Most do not fly from one place to another before being diagnosed and hospitalized. Few SARS cases to date have been traced back to exposures that happened on aircraft.
The biggest single kind of location for passing SARS on has been in hospitals. But most hospitals do not have SARS cases and so hospitals outside of areas which have a high level of SARS cases do not pose a risk as a source of SARS infections either.
The biggest danger from air flight comes from flying to a place that has a lot of SARS cases. Well, anyone who is worried about catching SARS should avoid visiting those (primarily East Asian) locations. The biggest danger to the rest of the world for SARS comes from the fact that people can fly from SARS-infected areas while still at early undiagnosed stages of infection. The greater danger from infected air passengers comes from the possibility that they will pass SARS along while staying for days at their destinations.
Public health experts are becoming increasingly pessimistic about the prospects for stopping the spread of SARS.
With infections now confirmed in two-thirds of China's provinces and mounting daily, ''hope dwindles'' for wiping out the disease, WHO virologist Wolfgang Preiser said from Shanghai. Even in ''Singapore and Hong Kong, very rich places, they still have problems. We are worried about the spread to poor provinces, maybe countries such as India and Bangladesh,'' where ''we don't think they have the capacity to stem the tide once it's introduced.''
''It may have happened already,'' he said.
Within the past day 3 new cases of SARS have been identified in India.
The Health Ministry has confirmed three more cases of SARS in India, which takes the total number in the country to seven. Of the three freshly confirmed cases, one is being treated in Kasturba Hospital, Mumbai, the second in Apollo Hospital, Kolkata and the third in Naidu Hospital, Pune.
If it was my decision to make I'd order the cessation of all commercial passenger flights between East Asia and the countries of the Indian subcontinent and Africa. Those countries do not have the capacity to contain SARS. They are too poor and most of their populations have little or no access to modern health care facilities.
Poor countries in the Indian subcontinent such India are unwilling to take sufficiently drastic steps to stop SARS in advance of a major SARS outbreak in their region. This is foolish. They lack the infrastructure needed to control SARS. As a result, the industrialized countries will have to adopt very rigorous measures at borders and ports of entry to detect SARS carriers because SARS is going to become endemic in much of the world. Thermal imaging and testing for SARS in all arriving and departing passengers will have to become routine at all ports of entry.
Reliable, accurate, and cheap DNA-based Real-Time Polymerase Chain Reaction (RT-PCR) SARS tests are the greatest hope the industrialized countries have for controlling SARS in a way that minimizes the economic impact. An ideal test would be able to use sputum so that a nurse would not be needed to draw blood. To allow testing of large volumes of business travellers an ideal testing device would need to be automated and have a high thru-put rate.
If all SARS carriers could be identified among international travellers even before they boarded aircraft to fly to a SARS-free country then regular business and holiday travel between SARS-free countries could proceed as normal. Also, anyone willing to risk going to an area where SARS is present would not need to be quarantined on return. Patterns of business meetings could be shifted to allow people from SARS-infected areas to travel to SARS-free areas to facilitate customer-supplier meetings. Then people in low risk areas would not have to travel to high risk areas to do business with the high risk areas.
If Taiwan could develop large-scale DNA-based SARS testing systems and use them to make Taiwan SARS-free then Taiwan could gain an advantage by making Taiwan as a place where mainland Chinese businessmen could travel to meet with businessmen from other parts of the world to do deals. Everyone coming to Taiwan could be tested before and on arrival for SARS virus. That way SARS carriers could be kept out. Business could be done in a safe environment fairly close to China. This would reduce the economic disruption that SARS is causing.
There are countries that are willing to take drastic steps. For instance, in order to keep out new cases of SARS Vietnam may close the 800-mile border it has with China.
Vietnam's northern Quang Ninh province, home of the Halong Bay tourist attraction, began barring Chinese tourists at its land border gates and waterways. Hanoi's health ministry has recommended the country seal all its borders with China indefinitely.
Countries that lack the capacity to fight SARS should be willing to close their borders to visitors from countries which have SARS cases.
The New York Times has an excellent long article that traces the spread of SARS. While China made huge mistakes in its handling of the crisis Singapore shines as a textbook example of how to aggressively quarantine and isolate potential SARS carriers.
But even in a small country, placing thousands on quarantine has been a strain. Last Monday, after a case of SARS was discovered in a vendor at Singapore's largest vegetable market, the Ministry of Health ordered all 2,400 food sellers to report for quarantine, up from a total of 467 quarantined before. Since 80 percent of the country's vegetables pass through the Pasir Panjang Market, restaurants were bracing for a shortage of greens.
Hong Kong has done a much worse job than Singapore in protecting health care workers.
In Singapore, with its aggressive system of identifying and isolating SARS patients, no health care worker has been infected for over three weeks. But in Hong Kong, 2 to 10 doctors and nurses are falling ill each day, in part, health officials there say, because doctors are still not identifying them as SARS victims early enough and are admitting them to ordinary wards.
Only recently -- weeks, if not months, after SARS hit -- have officials in China and Canada begun cordoning off entire buildings containing infected patients. Physicians such as Abraham Verghese say that slow response permitted the deadly virus to infect many others in their own countries and beyond. "The lesson of Hong Kong, China and, to some degree, Singapore is if you don't aggressively isolate, this thing can get out of hand," said Verghese, director of the Center for Medical Humanities and Ethics at the University of Texas Health Sciences Center at San Antonio.
Its apparent incubation period of two to 10 days is long enough for infected people who are asymptomatic to travel "from one city in the world to any other city having an international airport".
SARS is most likely a coronavirus. Other known coronaviruses can survive on surfaces for 24 to 48 hours.
Research done decades ago showed that the type of coronaviruses that cause many colds can remain viable on surfaces for 24 to 48 hours, depending on air temperature and humidity.
How long do coronaviruses survive in the environment?
In general, enveloped viruses such as coronaviruses do not last a long time in the environment. In earlier studies, a different coronavirus was shown to survive for up to 3 hours on surfaces. At this time, it is uncertain how long the newly discovered coronavirus associated with SARS can survive in the environment. In one preliminary study, researchers in Hong Kong found that both dried and liquid samples of the new coronavirus survived as long as 24 hours in the environment. Additional studies are under way to examine this important question.
People who live in areas where SARS is present should wash their hands frequently, avoid touching their faces or other parts of their bodies with their hands, and minimize the number of surfaces they touch in public areas. There are lots of ways to reduce one's need to touch surfaces. Do not use hand rails. Keep your hands on your lap when sitting in a public place. Use a stick or other object to press elevator buttons. Become more aware of where you are going and what you will have to touch in order to get there.
Update: If SARS does make it to the less developed countries the number of peope killed could be enormous.
With many cases still unresolved, a better current estimate of the deadliness of SARS may be the number of deaths as a proportion of resolved cases. Those numbers for Hong Kong, Canada and Singapore are 15.8, 18.3 and 13.7 per cent. But these too could be misleading if, for example, it takes longer to recover from a disease than to die from it.
There are other indications that the SARS death rate may be higher than expected. Mortality among infected SARS patients might end up being in the range of 8% to 15% of infected patients. Keep in mind that the death rate varies as a function of age and the death rate is higher in the elderly. Still, overall it is lookiing like the death rate from SARS is going to turn out to be at least 10%.
"If one looks carefully at the WHO figures on mortality and recovery rates, it is running, unfortunately, at 10 per cent," Professor Roy Anderson of Imperial College said.
Update II: Chinese infectious disease experts see a coming third bigger wave of SARS infections in China.
Bi and other experts have said that Beijing officials did not take adequate measures last week to stop Beijing's huge migrant labor population from returning home, and thereby possibly spreading the disease across China.
"The government held meetings for hours with no decision and meanwhile, everybody left town," Bi said. "Beijing is the second peak of the disease. The third one, in the countryside, will be much, much higher."
My fear about the coming third wave is that it will spread SARS into areas adjacent to China. Granted, most land borders of China are in pretty sparsely populated and harsh environments. But SARS could spread across Central Asia and eventually into more densely populated Asian countries.
Two more cases of Severe Acute Respiratory Syndrome (Sars) have been reported in India, taking the total number of people infected with the pneumonia-like virus there to nine.
SARS cases seem to be popping up in India daily. This is not good. All it would take is for one of these cases to be a "super-infecter" (also called "super-carriers", "super-spreaders" or "hyper-infecters" in some reports) for the disease to start spreading rapidly there.
Keep in mind that SARS cases in India are orders of magnitude more significant than SARS cases in more developed countries because India is far less able to control the spread of a disease. Places like Canada, the United States, Taiwan, and Singapore have the ability to identify cases, isolate them, trace those who might have been exposed, and generally take the steps that will eventually put a halt to the chain of spread. But if SARS makes it into areas where there are large numbers of poor people and primitive health care the disease will become a greater threat to the entire world. Pay especial attention to reports of SARS cases in the Indian subcontinent and Africa. The battle to prevent a global SARS pandemic will be won or lost in the poorest countries.
Growing fear of Severe Acute Respiratory Syndrome (SARS - also called atypical pneumonia in the Chinese media) has caused 1 million people to flee Beijing for other parts of China.
There was a continued exodus from Beijing today as thousands of people attempted to flee the epidemic and return to their home towns all over China. At the Beijing airport, travelers wearing face masks boarded planes out of the city. Local journalists estimated that almost 1 million people, about 10 percent of the population, had already left the capital.
This is an astounding figure. When is the last time that so many people took such drastic action in such a short period of time in response to a natural biological threat? Imagine how people would respond today to an even bigger infection threat. SARS does not spread as easily as influenza. Some day a new influenza strain that is more lethal than the typical influenza strains will arise. It could cause panic around the world.
The rush to flee Beijing has been fueled by the fear that the government would declare martial law and close off the city from the rest of China. The government has had to announce that it would not impose martial law but it is unlikely that the Beijing public believes it.
This is guaranteed to spread SARS further and faster. Infected people riding on airplanes, trains, and buses will pass the disease along to other passengers. They will also pass it on to people they have contact with at their destinations.
The treatment of those suspected of being exposed to SARS in Beijing is considered to be so harsh that people may be hiding their SARS symptoms from the authorities.
Sars suspects are being victimised in Beijing, where thousands have now been put in compulsory quarantine, a World Health Organisation specialist, Dr Wolfgang Preiser, said yesterday.
"If you make it hell for them, they go into hiding," Dr Preiser, a German virologist, told reporters in Shanghai.
While some might cheer the prospects of the Chinese government coming under intense criticism from its own population for the government's handling of SARS keep in mind that a revolution in China would by itself kill millions and that the chaos of a revolution would cause SARS to spread even faster.
Supermarkets reported a roaring trade in staples such as rice and cooking oil as rumors swirled the city would be isolated, while many other shops simply closed up as scared residents stayed at home.
At least this is a rational response. To reduce the risk of exposure in a high infection area it makes sense to buy a lot of food at a time and shop less often. It also makes sense to shop during the off-hours to reduce the number of people one is exposed to. If there was a big outbreak it would make sense to have open air markets so that the air would be dispersed quickly.
There is lots of bad news about Severe Acute Respiratory Syndrome (SARS). SARS is continuing to spread and to establish itself in more locales. The death rate has risen. It appears to mutate rapidly. There appears to be a more lethal strain that also infects the intestines and SARS is causing kidney failure in some patients. Tens of thousands of people (if not more) are fleeing Beijing and in the process helping to accelerate the spread of SARS to more parts of China. Effective drug therapies and vaccines are both distant prospects.
Different SARS coronavirus isolates have been sequenced and compared and many DNA sequence differences have been found.
The mutations were seen in all five of the viruses' known functional genes, with most of them occurring in the gene that carries the instructions for the distinctive spikes that jut from the outside of the virus, according to Siqi Liu, associate director at the Beijing Genomics Institute, part of the Chinese Academy of Sciences.
Those mutations on the outer coating are important because they can create new strains of the virus that are immunologically distinct. A person who has already been infected by SARS and recovered from it would be at risk of reinfection if exposed to a different strain of SARS that had undergone a lot of mutations in genes that code for outer layer proteins. Also, rapid mutation that generates immunologically different strains makes the job of development of vaccines more difficult and makes the period of protection from a vaccine version shorter.
"The ability of the virus to mutate has been a real problem in poultry vaccines. "The virus has the ability to change quite quickly - a vaccine might be suitable for a while, but not forever."
As I've previously posted, vaccine development time for SARS is measured in years. Well, this news that SARS is mutating rapidly will most likely lengthen the amount of time it will take to develop a vaccine. This is not good.
Rapid mutation can lead to more virulent strains. A more deadly SARS strain that attacks the intestinal tract may have already arisen.
The Amoy Gardens patients are three times as likely to suffer early diarrhoea, twice as likely to need intensive care and less likely to respond to a cocktail of anti-viral drugs and steroids. Even medical staff who caught the infection from Amoy Gardens patients are more seriously ill, Yuen said.
Tom Buckley, the head of the intensive care unit at Hong Kong's Princess Margaret Hospital, said organ failure was also now becoming more common.
"Initially patients were presenting with just respiratory failure," Dr Buckley said. "Now we're seeing renal failure and other organ failure."
Statistics in Hong Kong show that the death rate among people younger than 55 is 3.6 percent. For patients between 65 and 75, it is 18.9 percent. For those older than 75, the death rate is 28.6 percent.
The death rate from SARS in Hong Kong has increased to 7.2 per cent of reported cases - up from about 5 per cent earlier in the crisis - and officials fear it may go higher.
There are a number of possible reasons why the death rate is increasing. It could be that many of the initially infected tended to be healthy business travellers and health care workers. Now SARS is spreading from them to their families including older folks who are more at risk of dying from infections. Or the virus could be becoming more deadly as it mutates. Or some people may have been sick for weeks before finally succumbing. The real explanation may turn out to be a combination of factors.
CHINA: Beijing closed schools for two weeks and sent 1.7 million pupils home yesterday as the country struggled to contain a Sars outbreak thought to have originated in its south.
The 1,200 bed Beijing University People's Hospital was sealed off because of SARS today and police were posted to stop people going in or out, hospital staff said.
BEIJING, April 23 -- Thousands of people mobbed Beijing's West railroad terminal today in desperate attempts to flee the city as the capital reported another triple-digit increase in the numbers of people infected with SARS and nine more deaths.
But the relative safety of many of the provinces could prove shortlived if the infection is spread by the railway system.
If the infection is spread by the railway system? Why wouldn't it be spread that way? The infection is already being spread to many provinces of China. Surely some of that spread is happening via rail travel. But cars, airplanes, and other means of transportation are surely contributing as well.
When people start trying to get rail tickets for any place they can get a ticket for then real panic has set in.
Laden with burlap bags and potato sacks, they boarded trains for whichever destination they could get a ticket as the death toll jumped by 25 per cent in the Chinese capital.
Think about it. People are fleeing in panic from the capital of the world's most populated country. Most of the country has health care facilities that are primitive compared to Beijing's. People are spreading out to those more primitive places. My guess is that SARS will achieve pandemic status in China. The Chinese government's honesty (or lack thereof) in reporting SARS cases is becoming irrelevant as SARS spreads into the poorest areas of China. We will not know how many people in China have SARS because most of the future Chinese sufferers will be in areas too primitive for them to be seen by qualified medical professionals.
At least the people fleeing Beijing are trying to avoid enclosed areas where the risk of breathing airborne virus particles is greater.
A sea of faces in white cotton masks scanned coveted train tickets, waiting for hours outside in the chilly air rather than linger in crowded, enclosed waiting rooms.
BEIJING/TORONTO (Reuters) - Saying SARS was still spreading out of control, the World Health Organization tightened travel advisories on Wednesday, adding Beijing and Toronto to the list, while authorities in Beijing started quarantines.
Canada has responded angrily after the World Heath Organization (WHO) listed Toronto with Beijing and China's Shanxi province as places travellers should avoid because of the danger of Sars.
The Canadian government is being parochial. Steps to stop the spread of SARS need to be taken before it becomes an even bigger threat. The WHO should have gone much farther and told people to avoid China entirely. Plus, it should have asked that people in infected areas not travel from those areas.
China's government waited too long before acting. The spread of SARS to the poorer provinces of China makes it unlikely that the Chinese government will succeed now in stomping out SARS entirely. That, in turn, increases the odds that SARS will spread from China to even less developed countries. If SARS becomes established in India or, even worse, in Africa then it seems likely to achieve pandemic status.
The problem is that the more places SARS becomes established the greater the chance that on any given day there will be someone bringing SARS into areas where it hasn't become established. Plus, the greater the panic becomes the more people will flee infected areas and infected countries and carry SARS with them in the process.
The economic costs of trying to prevent the spread of SARS need to be weighed against the economic costs of what happens when it becomes established. In countries where SARS has taken root the economic costs of people becoming afraid to travel, go to jobs, meetings, and to go shopping in markets is becoming enormous. The Western industrialized countries need to work hard to prevent SARS from becoming big enough to start changing the behavior of a substantial portion of the population of each country. The economic costs would become staggering if SARS did come to be viewed as a threat to the population of the Western nations.
Countries should reduce the issuance of visas for people from infected areas. Some countries already are doing so. Saudi Arabia has stopped issuing visas to visitors from several East Asian countries. So has Israel. Belize has banned visitors from several countries including Canada. Singapore, Hong Kong, Tokyo-Narita, Beijing and other cities with international airports are installing thermal imaging systems to scan passengers for fevers. These are certainly steps in the right direction. More international airports should institute thermal imaging screening and other methods of screening incoming passengers. Unfortunately, it is the countries that are least able to afford to handle a SARS outbreak that will also be least able to afford extensive screening measures at their international airports.
Fast DNA-based SARS tests are essential for stopping the spread of SARS. As soon as fast DNA-based SARS tests become reliable the industrialized countries should use the tests extensively. At the very minimum, all suspected SARS cases and all their contacts should be tested and tested again. However, even more extensive testing regimes could be imagined. For instance, all people coming from infected areas could be tested or, for even more protection, all people coming into a country from any origin could be tested.
Infected areas that are relatively affluent and capable of carrying out fairly sophisticated measures to control SARS ought to consider testing their entire populations. For instance, Singapore's economic losses from SARS are so large and the benefits of being SARS-free are so large that once cheap and fast SARS tests become available city-state of Singapore ought to consider testing its entire population. Also, if a DNA-based test is not reliable within the first day or two of infection Singapore could consider putting people into quarantine for a day or two upon entrance into Singapore in order to test them again before letting them out into their general population. One way to make such a system workable would be to set aside hotels to use for quarantine and then to make each hotel receive only people who arrive on the same day with a rotating list of hotels looping thru the quarantine cycle.
The Eurasian land mass faces a more difficult task to contain SARS than do places that are geographically isolated with smaller populations. Countries like Taiwan, Australia, or New Zealand ought to be able to totally stamp out SARS and keep it out once fast DNA tests are available. But if SARS becomes established in Central Asia it will be able to jump across borders of impoverished countries and maintain its presence far more easily.
If SARS becomes established in countries that are significant sources of illegal immigrants then attempts to control SARS spread at borders of industrialized countries will become considerably more difficult. A SARS epidemic in Mexico would make SARS control in the United States much more difficult while a SARS epidemic in the Middle East or Africa would pose similar problems for Europe.
Update: The more industrialized countries ought to start taking more drastic measures now to help the poorer countries detect SARS sufferers entering their countries. For instance, an effort by the United States to help Mexico and Central American and Caribbean countries to screen international visitors for SARS infection (e.g. by training airport workers, providing thermal imaging machines, and eventually supplying help in testing passengers) will help the to prevent the spread of SARS into the United States. Either that or the United States had better be prepared to deploy troops on a massive scale to keep out illegal aliens coming up from Mexico potentially carrying SARS. That troop deployment may become necessary anyhow. SARS could be spreading in Mexico right now without our even being aware of it.
If the Asian Times staff are right China is already doing triage to decide in what parts of its country it will try the hardest to control SARS. The Chinese government may have already resigned itself to the wide spread of SARS into poor interior provinces and may be focusing its attention on Shanghai and other key trading and commerce cities. The industrialized countries need to start planning how they are going to keep a world SARS pandemic from reaching into their populations and disrupting the industrialized economies.
Update II: Time Magazine has an excellent article that confirms the widely suspected continued cover-up of SARS cases in Shanghai.
A doctor at the Shanghai Contagious Diseases Hospital told TIME that there are more than 30 suspected cases have been admitted to their hospital's facilities, nearly double the official suspected caseload for the whole city.
Basically, local authorities in China still are hiding the truth about SARS. Plus, in the poorer sections of China where SARS is spreading the local authorities will not even have the ability to know for themselves how many SARS sufferers there are. It sure looks like SARS is going to continue to spread thru China and therefore its chances of spreading to other parts of the world are probably increasing. The industrialized countries need to start scaling up to try to halt the spread of SARS into regions ill-equipped to handle it.
Once cheap fast SARS tests become available one great way to slow the spread of SARS would be to require the testing of all passengers on flights everywhere in the world. Also, all people crossing borders by other means should be tested as well.
The research by Professor Roy Anderson, due to be published in a medical journal next week, is expected to say the virus could kill between 8% and 15% - or one in seven - of those infected.
Keep in mind that SARS has a much higher death rate in the elderly. If you are young your own odds of dying from SAR woul be lower than this latest estimate and if you are old your odds would be much higher.
The fear of Severe Acute Respiratory Syndrome is causing an increasingly panicked response in Beijing China.
At Bank of China branches, there were no lines. The traffic at Western Station, the city's main rail terminal, has dropped 75 percent, to 80,000 passengers a day.
More than half of universities in Beijing said they would close indefinitely as the highly infectious disease spreads there.
It is important to remember that the coronavirus that is the probable cause of SARS is nowhere near as easily spread as influenza. Yet, as previous history demonstrates (most notably the 1918 Spanish Flu), very deadly influenza strains can infect the human population. Given that SARS can cause this degree of fear and panic and economic disruption then just imagine the effects on human behavior of an especially deadly influenza epidemic. Countries would close their borders. Cities around the world would become ghost towns. Natural biological phenomena still have the capacity to cause huge changes in the behavior of literally billions of people.
What I'd like to see come out of the SARS epidemic is a wider appreciation of the need to develop better capabilities to respond to natural disease outbreaks in the human population. Much of what needs to be done to prepare for natural disease outbreaks is also is helpful for handling bioterrorism attacks. Better monitoring systems are needed for both natural and man-made disease outbreak scenarios. Faster methods of identification and isolation and characterization of pathogens and faster methods for developing and manufacturing vaccines are all helpful for both types of scenarios. Advances in biotechnology are needed to speed up all the steps of response to a new disease.
Another area that needs to be looked at is how to allow people to carry out more of the normal activities of business and commerce with less exposure to other humans. What simple cheap things can be developed to allow people to move around and do things without coming into as much contact with surfaces other humans have touched or air that other humans have coughed particles into.
I can imagine all sorts of simple and cheap ways to reduce exposures. For instance, how about short sticks to use to press elevator buttons? Or how about more foot operated devices such as restroom soap squirters and water faucet operators so that people don't have to touch surfaces that other people touched?
Another important area that needs work is the development of better facial masks. This is an area that cries out for nanotechnological developments to create material that will filter air more efficiently and last longer. Masks should not become less efficient as they build up moisture from a person's exhalations of breath. Masks should be able to take more particles out of the air with less resistance so that breathing with them is easier.
Airline passengers arriving in Singapore from certain Sars-stricken areas are now being scanned for the disease by a military-grade thermal imaging camera, which will detect any increase in temperature, officials said.
One of the units is currently in use and another eight will be installed by the end of the week, Ong told The Associated Press.
Those who show up on the camera screen as “hot bodies,” or with a temperature greater than 37.5 C (99.5 F), will be pulled aside to have their temperature taken by a nurse, said government spokeswoman Evelyn Ong.
Singapore will also deploy thermal imagers to its border checkpoints with Malayasia. Other countries are following Singapore's lead as has been the case throughout the SARS crisis. Hong Kong's airport is also being equipped with thermal imaging to scan passengers.
In Singapore and Hong Kong, airports are being equipped with thermal imaging systems that can pinpoint feverish passengers
Thermal imaging is just one of the technologies being deployed in novel ways to fight the spread of SARS. The Ontario Province of Canada may join Singapore in placing electronic tracking bracelets on people exposed to SARS in order to monitor compliance with quarantine restrictions.
Dr. Young acknowledged the province is giving some consideration to putting electronic bracelets on people reluctant to stay in quarantine, as has been done in Singapore. "We're thinking about that and looking at that," he said. "There may be some legal issues involved."
Thermal imaging and electronic quarantine enforcement are just two of the ways that modern technology is changing how disease outbreaks are fought. The potentially most powerful tool in the modern epidemic fighting arsenal is DNA detection technology placed on DNA chips using low cost mass production. There are promising signs on that front.
Based on the discovered genetic sequence, the BNI has established a real-time PCR (Polymerase Chain Reaction) diagnostic test from which results can be obtained within two hours. From that test, artus developed a ready-to-use system (RealArtTM HPA-Coronavirus RT PCR Reagents) produced under GMP conditions (Good Manufacturing Practice). It will be available from artus and its subsidiaries in the USA and Malaysia from Monday, April 14th, on. Thomas Laue, project manager at artus says: "By providing this assay quickly, we hope to contribute to the standardization of SARS diagnostic worldwide. The early and rapid detection of the virus will be our small share in controlling this epidemic plague." The PCR assay directly detects parts of the new Corona virus in throat swabs, sputum and faecal samples. The RealArtTM HPA-Coronavirus RT PCR Reagents assay delivers results very quickly. The real-time PCR technique improves specificity, allows interpretation of results during the test and provides data about the quantity of the viruses in the sample material. Classical tests like antibody assays in blood allow detection of an infection normally much later, i.e. ten to twenty days after infection. The prompt results of the RealArtTM HPA-Coronavirus RT PCR Reagents assay allows immediate countermeasures by fast diagnosis, e.g. of travellers. By this, the rapid spread of the disease can be prevented.
Hot on the heels of the Artus announcement Singapore's Genome Institute has announced a 3 hour SARS coronavirus detection assay.
The state-run Genome Institute of Singapore said its new test would take three hours and may be sensitive enough to detect the virus in its early stages before a person develops Sars symptoms such as high fever and a dry cough.
How might the SARS outbreak be ended? Picture cheap, fast, and easy-to-use SARS virus detection tests that can detect SARS at a very early stage of infection. Such a test could be employed far more widely than quarantines. Everyone flying from an area where SARS has spread could be tested either before they get on the airplane or shortly after arrival at their destination airport and not released until their test shows a negative result. The same practice could be used at high risk ground border crossings as well. Plus, anyone found by either conventional thermometers or thermal imaging to be running a temperature could be tested and held until the result of the test is known.
If SARS testing could be made incredibly cheap then a more radical approach will become possible: test everyone for SARS. One could just test everyone in countries where SARS is spreading. Or one could, in the extreme, test the whole planet's population. If the testing was done in a relatively short period of time in a geographic area before non-tested people could pass along the virus to tested people then the disease could be eradicated from the human population in the area tested. Then in that area all people who entered could be tested.
Massive testing as a method to control the spread of a disease is easier to do for areas that are geographically isolated. For instance, it would be far easier to do this for Australia or Hawaii than it would be for a country on the Eurasian landmass. It would also be easier to do for areas that, for whatever reason, have little in the way of cross-border traffic.
The speed, cost, and ease of use of a test are not the only elements needed to make massive testing a feasible way to stop a dangerous disease outbreak. Another crucial element is the speed with which the test can be developed in the first place. SARS does not spread as rapidly as influenza and so it has not reached epidemic status in many locations. But the approximately 2 months that it has taken to develop fast tests for SARS (China knew about SARS 5 months ago but kept it secret and so the Western scientists have had only 2 months to identify the cause of the disease and to make tests for it) would be too long of a time for, say, a new and highly deadly influenza strain. However, it seems reasonable to expect that advances in nanopore technology, microfluidics, and other areas of biotechnology and nanotechnology will gradually shrink the amount of time it takes to identify a new pathogen and to sequence it. Once it is sequenced the creation of a new test for it can be done very rapidly.
What we are seeing in the response to the SARS outbreak is the development of elements of the future high tech public health disease fighting arsenal. Automated systems to detect disease and track human movement will only become cheaper and more powerful. Also, many other areas of relevant technology will surely see improvement. The current generation of facial masks will almost certainly be supplanted by greatly improved materials manufactured using nanotechology. The ability to protect a person from exposure will advance in a large variety of other ways including more advanced air filtration systems (again designed using nanotechnology), fancy personal instruments for monitoring individual health, and detection systems for airborne pathogens located in crowded public places. We may some day witness public health officials dispatched rather like police and emergency workers to quarantine an area and its occupants because a detector in some restaurant, airport, or hotel has signalled the presence of a dangerous pathogen.
Ultimately, just as technological advances have accelerated the rate at which diseases can spread other technological advances promise to entirely stop future epidemics at their very start. We may some day live in a future in which natural disease pandemics no longer happen.
You can read more about SARS from a more biological and public health perspective in my FuturePundit Natural Dangers Archive. For economic impacts see the ParaPundit Political Economics Archive. For what the response to SARS says about open versus closed societies see the ParaPundit Open Versus Closed Societies Archive.
As the number of SARS cases in China continues to increase and as SARS shows up in additional parts of China the Chinese leadership has begun to publically acknowledge the seriousness the problem.
"Since the discovery of the SARS cases, I feel very worried. I feel anxious for the masses," Chinese President Hu Jintao said today.
It was his first public comment on SARS and, in an unusual step, the national evening news broadcast his own voice instead of having an announcer read his comments.
``Much progress has been made in combating the disease, with the epidemic brought under control in some areas, but the overall situation remains grave,'' Mr Wen was quoted as telling a national conference.
These statements are being reported by the Xinhua News Agency and major Chinese newspapers. The Chinese population is still being told that the spread of SARS is being controlled. The official message is still that the government has a handle on the situation. But the problem has gotten large enough and so visible internationally that the Chinese leaders have had to come closer to admitting to their own people the full extent of the problem. It is likely that SARS cases known in Chinese hospitals are still going unreported to the World Health Organization. But it is becoming too hard to cover it up.
Previous official statements that China had SARS under control were scaring away foreign visitors who didn't trust the excessively optimistic picture the Chinese authorities were painting.
Foreign diplomats said the main reason for China's slightly more transparent line on Sars appeared to be a realisation that the previous blithe assurances were scaring more potential foreign visitors than they were reassuring. Mr Wen was now trying a different tack to limit damage to the country's economy.
The official acknowledgement of the scope of the problem may signal that the Chinese authorities are going to try harder to fight the spread of the disease. These comments from top leaders were accompanied by the announcement that China will begin screening rail and aircraft passengers for symptoms of SARS and quarantine suspected SARS cases.
The problem is that China has already lost its best opportunity to control the SARS epidemic before it reached pandemic status. China's best chance was to contain SARS where it started at an early stage. One obvious reason to try to stop a disease at its earliest stage of spread is that the smaller an area it exists in and the fewer infected by it the easier it will be to contain it. But the other less obvious reason is that SARS originated in the Chinese province best equipped medically to contain an epidemic.
Due to its proximity to Hong Kong the Guangdong province of China, the origin of the initial SARS infections, has industrialized much more rapidly than the rest of China. Therefore Guangdong is more affluent and this greater affluence has translated into greater wealth flowing into health care facilities in the province with more hospitals equipped with modern medical equipment, test labs, and drugs. The wealthier hospitals and clinics of Guangdong province have a greater capacity to handle SARS than is the case for the rest of China. Public health experts are quite aware of this situation. In their preliminary report of April 9, 2003 the World Health Organization team in China made note that as SARS spreads from Guangdong into the rest of China it is spreading into areas far less able to handle the disease.
However, the team found an urgent need to improve surveillance in the countryside to head off new outbreaks in rural areas. The team was further concerned by an increase in sporadic cases, which could not be linked to a particular transmission chain, as such cases raised questions about the adequacy of contact tracing. In addition, the report noted many remaining concerns about the ability of other provinces, where health systems are not as strong as the one in Guangdong, to respond promptly and effectively to the challenge of SARS. In Beijing, for example, only a minority of hospitals make daily reports of SARS cases. Contact tracing is another problem in Beijing and does not appear to be carried out systematically. Failure to perform careful contact tracing will allow the disease to spread. The team observed that many of China’s poorer provinces may not have adequate resources, facilities, and equipment to cope with outbreaks of SARS, and underscored that Guangdong’s capacity was exceptional among China’s provinces. In Guangdong, the SARS outbreak placed an enormous strain on the health care system. The Guangdong Infectious Disease Hospital (Guangzhou No. 8 People’s Hospital) had 150 of its 400 beds occupied by SARS patients daily during the second week of February. The team noted that the response of the health care system has been exemplary, and commended the dedication and bravery of doctors, nurses, and others working in clinics and hospitals.
Even wealthier Guangdong's handling of SARS is far from perfect. Poor people infected with SARS are being turned away from Guangdong area hospitals.
The man, who was also exhibiting symptoms of SARS, owed the hospital $250, said Chen's daughter, Chen Lili, who was visiting her father at the time. "They made him pack up and go," she said. "Who knows what happened to him? He had no money and he was sick."
These patients are sent home where they can spread the disease to family members and thereby continue the spread of SARS.
"We're very concerned about what may be happening out in the provinces," Henk Bekedan, director of the W.H.O. office here, said in an interview today.
The April 14, 2003 SARS update from the World Health Organization reporting new SARS cases in the Chinese northern province of Shanxi and in Inner Mongolia. This spread from the south to the very north suggests SARS is probably spreading throughout China.
China has today reported 109 new probable cases of SARS and 6 deaths, bringing the cumulative total to 1418 cases and 64 deaths. The largest number of cases occurred in Shanxi Province, where 47 new cases were reported. In addition, two provinces reported SARS cases for the first time – 10 in Inner Mongolia and 3 in Fujian. The reports indicate that the nationwide surveillance system, recently introduced by Chinese authorities, is working to detect and report cases. However, questions remain about the capacity of some provinces to cope with the challenge of SARS.
Today, officials in Shanxi said the province's local Center for Disease Control was instructed only last week to deal with SARS on an urgent basis. Only three hospitals in the province, all in the capital, Taiyuan, are able to handle SARS patients, officials said.
After 4 people travelling from Inner Mongolia showed up in the country of Mongolia to the north of China the Mongolian authorities responded by cutting off air and rail links to Inner Mongolian capital Hohhot.
The government said in a statement it had cut air and rail links to Hohhot for 14 days after four people with symptoms of the disease arrived from the capital of China's Inner Mongolia region, where three people have died of SARS.
Does anyone think there is the slightest chance that Mongolia and Inner Mongolia have the capacity to deal with SARS? This disease looks set to spread throughout the poorest parts of Asia. Now it is time to start looking for reports of SARS in Central Asia. Russia ought to start checking all rail and air passengers coming into Russia from China and Mongolia and ought to start checking those headed westward. But given how far SARS has already spread in China it seems only a matter of time before the disease spreads westward across China and into Tajikistan, Uzbekistan, and other countries in that region.
In spite of all this do you still feel optimistic that the spread of SARS can be halted? Well, South Africa wants rich Chinese tourists so much that it continues to encourage them to visit South African and it will not even screen them as they enter the country for signs of SARS.
Beijing - South Africa wooed Chinese tourists on Monday, saying they will not be barred from the country or subject to screening despite the spread of the deadly severe acute respiratory syndrome, or SARS, virus.
Picture SARS getting established in Africa spreading thru large populations of HIV sufferers with weakened immune systems. The lackadaisical South African government attitude toward SARS is grossly irresponsible.
The April 14, 2003 SARS update from the World Health Organization shows Hong Kong and China have 80 percent of all known SARS cases to date.
As of today, a cumulative total of 3169 cases of SARS, with 144 deaths, have been reported to WHO from 21 countries. This represents an increase of 213 cases and 25 deaths since the last update on Saturday. Indonesia, the Philippines, and Sweden report their first probable cases (1 in each country) today. Japan, which had previously reported four probable cases, was removed from the list as these cases were determined to have other causes. China, with 1418 cases and 64 deaths, remains the most seriously affected area. Hong Kong SAR, with 1190 cases and 47 deaths, is the second most seriously affected area. Three of the deaths in Hong Kong over the weekend occurred in persons under the age of 50, marking a departure from a previously pattern in which SARS caused deaths primarily in the elderly or in persons with pre-existing disease.
My guess is that China's SARS spread will accelerate while Hong Kong might be able to get it under control. The events in China may presage what will eventually happen in India, Africa, and other impoverished locales. If it gains a foothold outside of China in a poor country then SARS is very likely to become a pandemic.
One thing that Chinese health authorities ought to consider doing is to identify all people who have been exposed to and recovered from SARS. Then recruit those people to become health care workers to take care of SARS patients. Many of those who were infected with SARS in the first place were health care workers. So they already possess the needed skills. But the other recovered SARS patients could be trained in simple medical skills and work under the supervision of more skilled people who could tell them what to do.
A German biotech company has released the first SARS test which is based on the assumption that SARS is caused by a coronavirus.
The full coronavirus sequence will allow the development of faster, more accurate tests for SARS, using specific viral DNA fragments to prime PCR reactions. Early sequencing by the Bernhard Nocht Institute in Hamburg, Germany, has already helped the German firm Artus to produce a test that goes on sale on Monday.
The test can detect the virus from throat swabs, sputum or feces and produces results in two hours, say its makers, who specialize in disease test kits. They said classical tests for antibodies typically took 10 to 20 days after infection.
A HAMBURG BIOTECH company will release a real time PCR (polymerase chain reaction) diagnostic test on Monday which, it is claimed, can diagnose SARS (severe acute respiratory syndrom) in two hours.
What is good about a PCR-based DNA test is that it can detect a SARS infection at a far earlier stage than an antibody-based test. Therefore this Artus test is very good news.
A cheap fast SARS virus DNA detection test has the potential to at least keep SARS from becoming a big presence in the industrialized countries. The SARS virus might achieve pandemic status worldwide and yet the industrialized countries could mount a vigorous long term defense using testing to keep SARS from becoming established in the industrialized countries. Testing could be done to all people entering industrialized countries thru legal ports of entry to identify people who need to be sent into quarantine. People could be held in customs until their tests were completed. Also, anyone showing SARS symptoms or exposed to someone with SARS could be quickly tested. However, illegal immigrants would still serve as carriers of SARS into industrialized countries. Also, there would still be false negative test results among those at the earliest stages of infection. Plus, all tests have error rates. Still, widespread testing could limit the presence of SARS in the industrialized countries until a vaccine becomes available.
Lots of new strains of influenza first show up in China. The reason is that tens of millions of humans live in close contact with a large variety of farm animals in conditions which encourage viruses to jump between species.
Dongxing is just one example of how Guangdong's 80 million people live close to the animals, poultry and fish they eat. At another piggery close to Mrs Yang's, a farmer keeps young chickens next to his pigs. All the piggeries empty their waste into the ponds where shrimp and grass-carp are raised for the table.
In other places, battery chickens are kept above the pig pens, feeding their waste into the pigs' food troughs. The close proximity and cross pollution adds to the risk of animal viruses infecting humans, either directly or via pigs
Of course it would be great if Chinese farming practices were changed in ways that would reduce the chances of viruses jumping between species. But the farmers who engage in the dangerous livestock raising practices are poor and do not have a lot of alternatives. As China industrializes one can expect conditions to improve as agriculture industrializes, becomes more capital intensive and less labor intensive. With fewer people down on the farm fewer people will come into contact with pigs, ducks, chickens, and other farm animals.
Given that China is such a threat as an origin of new pathogen strains and of pathogen species that jump between mammalian species it would also be great if the Chinese government was really eager to pursue proper public health policies for controlling epidemic disease outbreaks. However, as I explained in my ParaPundit blog posting Repressive Governments Make Fight Against SARS More Difficult the Chinese government, being a repressive regime that has lots of motives to cover up the truth, has plenty of reasons to mishandle an epidemic disease outbreak.
In spite of my previous readings and writings on why the Chinese government does what it does I was still floored to read that the Chinese government is currently trying to encourage domestic tourism as a way to assure international travellers that China is a safe destination.
Despite the risk of spreading the disease across this country, the government thinks that a successful May 1st holiday will help convince international travelers that China is safe, Chinese officials said.
Hong Kong is less an open society than it used to be but it is sufficiently open that scientists there are openly discussing the possibility that SARS will not be stopped.
Samson Wong, a microbiologist from Hong Kong University, said that Sars might infect 80 per cent of the population within two years and eventually everyone could be infected. A Health Department spokeswoman said that the possibility could not be ruled out but declined further comment.
What is making infectious disease experts less optimistic that SARS will be contained is the inability to trace some SARS cases to person-to-person contacts. This has led scientists to speculate that SARS may in some cases be spreading by cockroaches, sewage, contaminated surfaces such as door knobs, and by other means.
But in recent days, epidemiologists have been unable to trace a number of SARS outbreaks in hotels, hospitals and apartment complexes in Hong Kong, Singapore and China to such person-to-person spread.
In the face of such scientific uncertainty the Chinese government continues to be irresponsible in its handling of the SARS outbreak. It may become necessary for more governments to follow the example of Malaysia and start restricting travellers from Hong Kong and China.
Very few SARS cases have been reported in India so far. However, if SARS becomes established in India it will be very hard to stop.
"Our health system is very inadequate and it will be extremely tough to control the disease if it arrives," Anil Bansal, president of the Delhi Medical Association, told Reuters.
The very limited health case system in India makes the news about SARS coming from India very important. Therefore every suspected SARS case in India is watched very closely.
Not all suspected SARS cases in India have turned out to be SARS. For instance, Maria, the first suspected SARS case in New Dehli, may have a different kind of infection.
"She has been provisionally detected of having acute pharyngotonsilitis,’’ said Dr R.N. Salhan, the hospital medical superintendent.
Also, a 23 year old American woman suspected of having SARS in Bombay turned out to have a less dangerous illness. However there are at least two other suspected SARS cases in India including a 48 year old Indian national recently arrived via Singapore.
A 48-year-old software worker was admitted to hospital in Hyderabad on Tuesday after he arrived from Australia via Singapore with high fever, a cough and cold -- symptoms of the virus that has killed more than 100 people worldwide.
Surely the government of India can afford to quarantine and treat a few thousand sufferers. India is making efforts to be prepared to do so.
Facilities have been created for treatment of SARS cases in isolation in the Central Government hospitals as also in other Infectious Disease Hospitals. Health care facilities at International Airports and Ports have been strengthened by deploying additional doctors and evolving a standard operating protocol.
But the problem for India is that there are hundreds of millions of poor people who have little or no access to medical doctors and medical tests. If a single SARS sufferer reaches India and if that sufferer happens to be very infectious the results could be disastrous.
A single SARS sufferer is all it would take to rapidly cause a large SARS outbreak in a primitive country. "Hyper-infectors" (a.k.a. "super-carriers") of SARS may have been responsible for the big SARS outbreak in the Toronto Canada area.
Canada's SARS outbreak has been fuelled by three "hyperinfectors" who each passed on the disease to 20 or more other people -- a phenomenon never before seen with a virus, experts said yesterday
It is noteworthy that all three of the hyper-infectors in Canada died. Could it be that the more severe form of the disease is more infectious? Perhaps the people who have the severe form cough more and therefore generate more airborne particles which contain active virus.
Individuals who are inordinately infectious have been seen with certain types of bacteria, but not viruses, said Dr. Low.
Africa has the same vulnerability to SARS that India has. Therefore SARS cases in Africa are incredibly important to watch for. A Pretoria South African man who travelled from Hong Kong to South Africa on March 27 is hospitalized and suspected of being a SARS case.
A 62-year-old South African man is being treated at a Pretoria hospital as a "probable SARS" case, according to officials.
One factor that is doing a lot to reduce the chances of SARS spread is the great reduction in air travel. Given India's greater vulnerability to SARS Air India's 60% reduction in flights between Hong Kong and Bombay (Mumbai) is good news.
It further curtailed its services to Hong Kong, and will now operate only two flights a week (on Mondays and Fridays) as against the scheduled five flights a week.
While voluntary decisions to not travel are playing a role in efforts to reduce the risk of further spread of SARS government decisions can block off means of spread by more dramatic means. In order to reduce its risk of getting SARS cases from China the government of Malaysia is no longer granting tourist visas at its diplomatic facilities in China.
Malaysia has taken the draconian step of banning all tourists from mainland China to try to stop the spread of the deadly Sars virus.
India and Africa have greater need to take such a dramatic action than Malaysia does. If tourist travel was cut off other types of travel could still be allowed but under much more stringent rules. In the extreme, countries could allow passengers to travel from other countries but then force them into quarantine for 7 to 14 days upon arrival. This would provide a way for people who plan longer term changes in residence to still move around to take different jobs.
Update: On April 17, 2003 a confirmed case of SARS was found in Goa India.
Goa's chief minister, Manohar Parrikar said that a 32-year-old marine engineer had tested positive for the virus and was being treated at the Goa Medical College. The man is said to have arrived in Goa earlier this month after travelling in Singapore.
The worry has to be that this fellow may have already passed on SARS to other people after he returned to India. SARS may now be on the loose in India. If that is the case the odds of containing it there are low. If SARS becomes pandemic in less developed countries the effect on the world economy would be to cause world recession.
CALCUTTA, April 26 (Reuters) - A 42-year-old Indian man has tested positive for SARS, authorities said on Saturday, the country's sixth case of the virus that has killed at least 289 people and infected about 5,000 worldwide.
The search for the cause of Severe Acute Respiratory Syndrome (SARS) has been greatly sped up by the use of DNA microarray gene chip technology. UCSF Assistant Professor Joseph DeRisi built a gene microarray containing all known completely sequenced viruses and used it to classify a pathogen isolated from SARS patients as a coronavirus.
DeRisi placed his computer's cursor over one lit dot and it read "bovine coronavirus." Another dot outputted "avian coronavirus." By the time he got to the turkey and human coronavirus dots, he knew he was dealing with something the world's scientists had never seen before.
If it had been a known virus — say the human coronavirus, a cause of the common cold — then only human coronavirus dots would have lit up.
DeRisi discovered that SARS is genetically most similar to a virus that infects birds.
Its genetic sequences so far seem to have the most in common with Avian Infectious Bronchitis Virus, according to preliminary molecular data obtained by Joseph DeRisi at the University of California at San Francisco and circulated among virologists.
Working with MIT post-doc David Wang and one other colleague (whose name I haven't been able to locate) DeRisi built a DNA gene microarray chip with the DNA of 12,000 different viruses. This allowed DeRisi to classify the suspected pathogen within 24 hours of the time he received a sample from scientists at the CDC. Let's put that in perspective. It took months to identify the pathogen that caused Legionnaire's Disease back in the 1970s. While DeRisi's assay was only one step of the process of isolation (it had already been tentatively identified as a coronavirus by viewing it with an electron microscope) it was a step that enormously accelerated the overall process.
DeRisi's development of a robot to place DNA samples onto the DNA gene microarray chip was helped along by advances made to do silicon semiconductor chip manufacture.
In fact, the robots that "pick and place" each sample from a small reservoir onto its spot on the slide are descendants of the machines used to build electronic chips.
This demonstrates a recurring FuturePundit theme: advances in electronic technologies are accelerating the rate of advance of biotechnologies.
The role that DeRisi and his colleagues played in identifying a coronavirus as a suspected cause of SARS came to the attention of the national media when CDC Director Dr. Julie Gerberding mentioned the work in a March 24, 2003 press conference.
But in addition, we're collaborating with academic partners. Earlier this week, we sent DNA out to a laboratory at the University of California, San Francisco, so that they could do the absolute state-of-the-art probe for virus genes and help us identify the cause.
Dr. DeRisi has made a more general contribution to the acceleration of the use of gene array technology. He built and released to the world the design of a robot that automates the process of putting DNA samples into gene arrays.
The technology behind the hope works by hybridization, the affinity for complimentary strands of DNA (cDNA) to form double helix structures. More than 40,000 unique DNA samples can be printed on glass slides in pre-determined locations.
DeRisi designed a robot that, at top speed, prints 14,400 elements per minute. These slides are then used to assay fluorescently labeled cDNA from tumors or organisms, like malaria, which are then stored on computers. Comparing these profiles can reveal the unique molecular signature carried by each type of cancer and give clues as to the original defect.
Despite the central role he played in revolutionizing genomics, it was DeRisi's populist approach to science that made him the buzz among academic and industry scientists. DeRisi never pursued a patent for the robot, instead he posted instructions on how to make it on the Internet.
"Joe could be a very rich man if he kept things to himself," says David Wang, a postdoctoral fellow in DeRisi's lab.
What we still need are advances that will accelerate the rate at which vaccines can be developed. Vaccine development time for a disease like SARS is still measured in years. West Nile virus, for which vaccine development was begun in 1999, killed 277 Americans last year while leaving many others with central nervous system damage. Yet a vaccine for West Nile virus will begin undergoing preliminary testing on humans in June 2003, it is still three to five years away from general availability.
There's still a way that an infectious pathogen which is passed human-to-human like SARS can be defended against using biotechnology: be able to quickly and cheaply identify who is infected so that the infected people can be isolated. This can break the chain of infection and prevent a disease from developing into a pandemic. Without a test to identify exactly who is infected all people who have contact with an infected person must be put into quarantine regardless of whether they really are infected. Singapore has used this aggressive standard technique for epidemic control with considerable success. However, because an infected person can come into contact with a great many people who do not themselves become infected public health authorities are reluctant to quarantine them all. A test to identify people who are infected could make quarantine regimes far more acceptable and effective.
What is needed is a test that can identify infected people at a fairly early stage of the infection. Most of the SARS tests currently under development can not detect the infection at an early enough stage.
The development of a diagnostic test, which is being pursued around the clock by the WHO collaborating network of 11 laboratories, has proved more problematic than hoped. Three diagnostic tests are now available and all have limitations as tools for bringing the SARS outbreak quickly under control.
The ELISA detects antibodies reliably but only from about day 20 after the onset of clinical symptoms. It therefore cannot be used to detect cases at an early stage before they have a chance to spread the infection to others. The second test, an immunofluorescence assay (IFA), detects antibodies reliably as of day 10 of infection, but is a demanding and comparatively slow test that requires the growth of virus in cell culture. The presently available PCR molecular test for detection of SARS virus genetic material is useful in the early stages of infection but produces many false-negatives, meaning that many persons who actually carry the virus may not be detected – creating a dangerous sense of false security for a virus that is known to spread easily in close person-to-person contact.
What is needed is an advance in biotechnology that will provide a test for SARS with high sensitivity at a very early stage of infection.
(thanks to Hylton Jolliffe for the first link)
Experts in public health and infectious disease are beginning to say that they believe SARS is more likely to spread to pandemic levels than to be contained.
"Most people are hesitant to say it will just go away," said Dr. Ruth Berkelman, head of Emory University's Center for Public Health Preparedness and Research. "Too many people are infected to think we won't see it for a long time to come."
In an editorial in The New England Journal of Medicine US CDC Director Dr. Julie Gerberding thinks it would require extreme luck for SARS to be controlled.
"If we are extremely lucky, the epidemic will be curtailed, develop a seasonal pattern that will improve prospects for regional containment, or evolve more slowly than it has at this early stage," Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention, wrote in an article this week.
"If the virus moves faster than our scientific, communications and control capacities, we could be in for a long, difficult race."
Note that her extreme luck scenario is for SARS to be controlled, not eliminated.
Dr. Donald Low (who is currently in isolation having himself been exposed to SARS) thinks SARS will become pandemic (i.e. widely spread).
"Unfortunately, it's an epidemic now that will become a pandemic," predicted Donald Low, chief microbiologist at Toronto's Mount Sinai Hospital.
Dr. David Heymann of the World Health Organization thinks we won't know whether we can contain SARS until we have a reliable test for infection.
"I think we've got to keep going at this speed until we get that diagnostic kit in use and figure out what's going on," Heymann said. "Then we'll know if we've lost or not."
One reason for the increased pessimism is the growing belief that some SARS sufferers are high infectious "super spreaders".
The four-member team is most interested in "the phenomenon of 'super spreaders' -- people who seem to spread their disease to a lot of other people," said the WHO team leader, Dr. Robert Breiman.
It is possible that co-infection with another pathogen makes a person into a "super spreader".
"It raises the question of, if you have one pathogen and you get hit with, say, coronavirus . . . are you more likely to transmit? Do you become what we call a 'super spreader?' " Breiman said.
Chinese scientists see evidence in some SARS sufferers of a rare airborne chlamydia bacteria that may be turning people into super spreaders.
Dr Robert Breiman, also of the WHO, said he feared people who already had chlamydia might be vulnerable to the flu-like bug and become highly contagious "super-spreaders".
Governments are moving to increase their quarantine powers. George W. Bush has signed an executive order giving public health officials the legal power to quarantine SARS victims. The Australian government has also moved to grant public health authorities power to force people into quarantine and even to close borders.
It seems likely at this point that decreased travel levels, use of facial surgical masks, and other responses to SARS will be longer lasting and spread to more locales. The economic cost of SARS then seems likely to increase substantially. If containment turns out to be impossible other defenses become more important.
Vaccines would be the ideal next line of defense but the very earliest we could expect help from a vaccine is a year from now. Since SARS is most likely a virus and anti-viral drugs are very difficult to develop the prospects on that front are not hopeful either. The best potential treatment is gamma globulin taken from the blood of people who have recovered from SARS. That may lower the fatality rate of SARS though likely only in industrialized countries and among elites in less developed countries. SARS could become pandemic in less developed countries and travel from those countries to industrialized countries could continually reintroduce it into the countries whose public health infrastructures allow them to stop its spread. Think of a series of fire alarms continually going off all across the industrialized countries as small outbreaks cause a series of small scale quarantines. That might turn out to be our future until a SARS vaccine is developed.
Another possible avenue of treatment is to find a way to suppress the most deadly symptom of SARS: the accumulation of fluids in the lungs which caused SARS to initially be called atypical pneumonia. The key to prevention of the fatal accumulation of fluids may be to find a way to suppress the production or sensing of the natural inflammation signalling compounds called cytokines. It is too early to tell whether steroids (which also suppress immune response) can suppress cytokines enough without suppressing the immune system too much.
With containment looking less likely, the availability of vaccines too distant in the future, and the development of drug regimens that prevent fatal consequences still in doubt the best response to SARS may turn out to be widespread changes in lifestyles and work habits to decrease the chances of spread. The widespread wearing of surgical masks as now seen publically in Hong Kong may spread to other areas where SARS takes hold. Health checks on airline passengers and the wearing of surgical masks on air flights might also become commonplace. The air filtration systems in many commercial and residential buildings may be quickly upgraded to prevent airborne virus spread.
Here's where the effect of SARS may become counter-intuitive: Because it kills only 3 or 4 percent of its victims a widespread public reaction that seeks to reduce the risk of exposure will have the added benefit of reducing the spread of influenza. This could lead to a net reduction in total deaths caused by infectious diseases because estimates of the yearly death toll in the United States from influenza run from 20,000 to 36,000 on average. The yearly death toll estimated as due to influenza in Canada runs from 1,500 to 4,500. Other industrialized countries have similar yearly death tolls from influenza proportionate to their populations. However, since influenza is more likely to kill the elderly the numbers also vary depending on the age distribution of the population and on the rate of yearly immunization. Also, death from influenza does not take as many total years of life away as a disease that strikes people down at a younger age. Still, if the populations of industrialized societies take drastic measures to reduce their risk of getting SARS one likely side effect should be a reduction of the death toll from influenza and possibly from other infectious diseases as well. Even those who are not at risk of dying from influenza will enjoy the benefit of being sick less often and employers will suffer lower amounts of lost work days and reduced productivity days due to sickness.
Update: A doctor in Hong Kong says Westerners fleeing Hong Kong are helping to spread the SARS virus more widely.
Dr David Stirling, told The Telegraph that families trying to escape the outbreak of the incurable illness - which has killed 80 people worldwide - were now the most likely reason for the spread of Severe Acute Respiratory Syndrome.
Update II: Time Magazine has an excellent article that compares the approaches used by Singapore and Hong Kong to respond to the outbreak of SARS. The far more aggressive measures pursued by Singapore resulted in the control of the outbreak.
When new cases were discovered, a team of 100 "contact tracers" tracked down not only patients' immediate families, friends and neighbors but also their office colleagues and favorite food hawkers, and placed them in quarantine, too. Anyone suspected of having SARS is transported to the hospital in an ambulance.
Singapore's far more aggressive approach toward identifying patient contacts and quarantining them has led to a decline in the number of new SARS cases in Singapore. It still may be possible to contain SARS if that aggressive approach is applied in other areas of SARS outbreak.
Update III: SARS may have gotten spread thru the Amoy Garden apartment complex in Hong Kong via cockroaches. If this turns out to be true then it will make SARS harder to contain.
WHO deputy director Alan Hampson, said the disease could be like AIDS with treatments taking years to develop. "It would take years to develop an anti-viral drug," he said. "The earliest you can expect a vaccine is in a small number of years."
Reinhard Kurth, the head of the German government's Robert Koch Institute, was not exactly encouraging on Friday night. A vaccine for Sars could be developed, he said – but it would take three to five years.
US National Institutes of Health NIAID director Anthony Fauci offers the best case timeline for SARS vaccine development of at least a year.
If it turns out that some other virus is at work, those researchers will have to start again, cautioned Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease. Even under the best-case scenario, he said, a vaccine is at least a year away.
Clearly, for the foreseeable future the only real option for the halt of the spread of SARS is to identify and isolate its victims quickly and to minimize the chances of exposure in locations where SARS is known to be present.
If you think SARS is bad just keep in mind that it does not spread as easily as influenza does. If SARS was caused by influenza tens of thousands would already be dead.
"If SARS were an influenza pandemic," says Melbourne University professor of virology, Ian Gust, "and the mortality rate was similar to what it is now (about 3.5per cent), we would have tens of thousands of people dead, rather than less than 100." And that is not because the virus would be any more potent, but because it would be much more contagious.
An extremely virulent form of influenza, the kind that only comes once every several decades, could end up infecting almost half of the population of industrialized countries. With a fatality rate similar to that of SARS it could easily kill one percent of the total population. The 1918-1918 so-called Spanish flu (which really didn't originate in Spain) With a world population at the time of 1.8 billion and with a low end estimate of the number killed by Spanish flu as 20 million the low end of the percentage of the population killed by the Spanish flu was at least 1 percent.
Although the history of flu epidemics is non-mathematical, in this case, as Voltaire might say, the superfluous is very necessary. In 1918, when the world population was 1.8 billion, an influenza epidemic incapacitated 1 billion and killed 20 million, all within the space of 8 weeks.
With a world population of 6.3 billion and a current annual growth rate of 1.16 percent a flu pandemic comparable to the 1918 Spanish Flu would kill somewhere in the range of 60 to 150 million people. This would be approximately equal to about one to two years of world population growth at current growth rates.
The most intense, to date, occurred in the last year of World War 1: the so-called "Spanish Lady" or "Spanish Flu" pandemic of 1918-19 which infected one billion people, half the world’s population at that time, and killed between forty and fifty million. This makes it the most devastating disease of man known, surpassing even the bubonic plague of the fourteenth century, smallpox in the sixteenth century and the human immunodeficiency virus/AIDS pandemic that is happening now.
Given the fatality rate of SARS infections we are lucky that SARS is not as easily spread as influenza. Still, there is reason to be concerned about the spread of SARS because there are cases of SARS which do not fit the more optimistic model of a requirement of close contact for SARS to spread.
Five of the 24 cases of Sars (Severe Acute Respiratory Syndrome) in the southern Chinese city of Foshan examined so far by a newly-arrived World Health Organization (WHO) team were caught despite the patient having no obvious contact with an infected person.
The biggest defense we have against a highly deadly influenza pandemic is the speed with which influenza vaccines can be developed against threatening new influenza strain.
(MEMPHIS, TENN.--April 2, 2003) Scientists at St. Jude Children's Research Hospital announced today the development of a vaccine against H5N1, a new lethal influenza virus that triggered the World Health Organization (WHO) to declare a pandemic alert in February 2003.
The virus appeared in birds in Hong Kong late last year and subsequently killed one of two infected people with rapidly progressive pneumonia in the past month. St. Jude developed the vaccine in only four weeks from the time it received the H5N1 sample from colleagues in Hong Kong.
The announcement comes at a time when a second, as-yet-unidentified virus, has taken several lives around the world. The unknown virus, which causes severe acute respiratory syndrome (SARS), appears to have originated at the same time and in the same place as the new "flu."
The development of the initial ("seed") batch of H5N1 vaccine is significant because humans do not have a natural immunity to the virus, according to Robert Webster, Ph.D., a member of the Department of Infectious Diseases at St. Jude. Rather, humans appear to become infected through contact with chickens and other birds. In the past the virus killed only the chickens it infected. But the new variant of H5N1 also killed many kinds of wild birds, which is unusual.
Even if a new vaccine could be developed rapidly to counter a killer influenza outbreak the problem today is that there would not be enough production capacity to make influenza vaccine for everyone. However, as demonstrated in US Health and Human Services Cabinet Secretary Tommy Thompson's March 27, 2003 testimony to the US Congress House Committee on Energy and Commerce & House Select Committee on Homeland Security the United States government is funding research to develop vaccine production technologies that are more easily scalable than current vaccine production techniques.
For example, the President's budget foresaw and prepared for an influenza outbreak. It proposes to spend $100 million to ensure the nation has an adequate supply of influenza vaccine in the event of a pandemic. Due to the constant changes in the circulating influenza strains, we cannot stockpile influenza vaccine, and the current manufacturing methods might not meet the Nation's needs in the event of a pandemic.
Funds will be used for activities to ensure a year-round influenza vaccine production capacity and the development and implementation of rapidly expandable production technologies. We will work closely with industry to accomplish these goals.
More scalable vaccine production techniques also have obvious anti-bioterrorism applications. Therefore the development of better vaccine production capabilities have been given an added spur by the rising awareness of the threat of bioterrorism.
Three months after SARS first appeared in China but almost a month before it started causing deaths in Hong Kong a Loudon County Virginia woman recently returned from Guangdong province China came down with what appears to have been the first American case of SARS (Severe Acute Respiratory Syndrome). On February 17 2003 after showing up in the emergency ward of Loudoun Hospital Center she was placed in a sealed room and the health care workers who treated her work protective gear in order to avoid infection.
In the emergency room, she had a high fever and a cough and was having trouble breathing. She and a relative mentioned that she had been in Guangdong and that a flu seemed to be going around there. A triage nurse put the woman in a sealed room that had a dedicated ventilation system to prevent her from passing along the infection.
The details of how she was handled read like a textbook approach for how to handle an unknown and potentially dangerous infectious illness. The Loudoun Hospital Center folks had the assets needed and made the right call.
The Washington Post has a good report laying out the events inside the Chinese government as it covered up the outbreak of SARS.
The outbreak of the illness is a revealing case study in how China's authoritarian government, which seeks to maintain a monopoly on power and control information, concealed vital data about a life-threatening disease from the Chinese people, according to doctors, health officials and journalists familiar with the events.
China is the place where the holding back of information on epidemic outbreaks promises to be most threatening to the world as a whole. Because of the millions of people (tens of millions? hundreds of millions?) in Southern China who live in close proximity with pigs, ducks, and other fowl China is like a big experiment for the mixing of DNA across different virus strains that normally infect different species. In the case of SARS it is likely that a human coronavirus coinfected a cell (probably in a human) at the same time a coronavirus from another species did as well. Genes were exchanged and the result was a coronavirus that is more lethal to humans. This also happens with influenza viruses. The most lethal influenza viruses are either viruses that jumped over from other species or which exchanged DNA with viruses from other species.
Because China has such ideal conditions for gene swapping between virus strains from different species it is more likely than any place on Earth to be the source of the next killer virus whose lethality would rank up there with the 1918-1919 Influenza pandemic that killed 20 to 40 million people. The authoritarian impulses of the Chinese authorities to control and hush up bad news, as they have done with the SARS pathogen, put the rest of the world at much greater risk to every new disease that first shows up in China. This impulse on the part of the Chinese government deserves to be widely and loudly criticised. The rest of the world needs to make it clear to China that this kind of "hush it up" reaction to disease outbreaks will not be tolerated because it creates an unacceptable risk to the health of all of humanity.
While the Chinese government prevented Chinese newspapers from reporting on SARS Dan Gillmor reports that text messaging using mobile phones helped spread the knowledge that SARS was a threat.
I found the Dan Gillmor link in a SARS link collection by Ian Mckenzie.
Update: Health care workers in Beijing are reporting 50 cases of SARS in spite of the fact that the last report from China to the WHO reported only 12 in Beijing. China is still being slow about admitting the extent of its SARS cases.
The additional cases have not been reported to the World Health Organization, even though Chinese health officials promised to begin daily reporting of such statistics this week.
Update II: The Globe and Mail has an excellent story on how the Chinese government tried to keep secret the spread of SARS.
But information was not shared with other health departments in this province of 80 million people. Instead, the Heyuan paper printed this statement on Jan. 3 from the local health bureau: "No epidemic disease is being spread in Heyuan. . . . Symptoms like cough and fever appear due to relatively colder weather." That was apparently the first report on SARS in the Chinese media.
Update III: In a move that is extremely rare for China the director of the Chinese CDC apologized for the Chinese government's handing of SARS.
"Today, we apologize to everyone," said Li Liming, director of the Chinese Center for Disease Control. "Our medical departments and our mass media suffered poor coordination," he said. "We weren't able to muster our forces in helping to provide everyone with scientific publicity and allowing the masses to get hold of this sort of knowledge."
While this apology has been broadcast in Hong Kong it is not clear whether people in mainland China heard it.
Li's statement was not immediately reported by Chinese media. It was not known whether his remarks were authorized by senior officials or whether Li, highly regarded in his field, had taken the unusual step of articulating the widespread view on his own. Other officials who have released unauthorized material about SARS have lost their jobs
In an encouraging sign that the Chinese leaders have perhaps learned that they can't go keeping major disease outbreaks secret the Chinese Deputy Prime Minister made noises about being a lot more open the next time around.
Deputy Prime Minister Wu Yi called for "the immediate establishment of a national medical emergency mechanism, with emphasis placed on a public health information and an early warning reporting mechanism".
There are 100 suspected cases of SARS (Severe Acute Respiratory Syndrome) in the United States with no deaths reported so far. By contrast, as of April 3, 2003 the World Health Organization has reported a cumulative total of 2270 SARS cases and 79 deaths.
Chinese authorities had previously reported a cumulative total of 1153 cases and 40 deaths in Guangdong Province from 16 November, when the outbreak began, to the end of March, making this province the area most seriously affected by SARS to date.
As of today, a cumulative total of 2270 SARS cases and 79 deaths have been reported from 16 countries. This represents an increase of 47 cases and 1 death (in Hong Kong) compared with yesterday.
Why the different death rates? Is the lower US death rate a reason to be complacent? Probably not. One reason is that US Centers for Disease Control and Prevention uses a different set of rules for identifying suspect SARS cases.
The majority of U.S. residents with SARS have recovered or stabilized clinically without specific antiviral therapy. The U.S. case-fatality proportion is lower than that reported in some other countries (3). Possible explanations for this include differing case definitions among countries or differences in the sensitivity of surveillance, leading to identification in the United States of patients with less severe or early manifestations of infection or of a larger proportion of patients with other respiratory illnesses. Until confirmatory laboratory testing is available, the case definition will include clinical criteria more likely to identify potentially infectious persons. Various therapies, including antiviral agents (e.g., oseltamivir or ribavirin) and corticosteroids, have been administered to SARS patients, but the efficacy of these therapies has not been determined.
Director of the CDC Dr. Julie Gerberding provides additional background on US CDC versus WHO SARS classification rules.
But with respect to your second question, why are the case patients in the United States having relatively mild illness, this is a conscious decision on our part to include anybody with fever and a respiratory symptom who had traveled to an affected area. The cases that WHO is including from countries on its list--at least most of the cases that are formally appearing on the WHO list--are only people who have the severe form of SARS, with the pneumonia. And so we are casting a broader net in this country because we want to be vigilant about identifying anyone who could possibly be infectious, and isolating them if they're sick, and advising their contacts how they can protect themselves. So not surprisingly, we do not have as many patients with pneumonia. In fact, I think we have altogether--I'll have to get back to you on the exact number, but less than 50 percent of our case patients have had pneumonia. And one of our case patients has required ventilation. But most of that is the artifact of the way in which we are conducting our evaluation and our epidemiologic assessment. Actually, about 20 of the case patients have been diagnosed with pneumonia.
Once an accurate test for SARS infection becomes available (and it looks like scientists are fairly certain that a coronavirus is the cause) then methods of classifying SARS victims can become more uniform. Dr. James Hughes of the CDC reports on progress in the development of SARS tests:
DR. JAMES HUGHES: In terms of the serologic testing, realize that 10 days ago we didn't have any antibody test to detect evidence of infection with this previously unrecognized corona virus. As a result of a lot of hard work that's been done here over the past 10 days, we now have two that look promising. One is an indirect fluorescent antibody test, and the other is an Eliza. More work needs to be done to validate these tests. I would remind you that these are tests that are not approved for routine use for patient diagnosis yet--not surprisingly, since they've just been developed. So we have to interpret results using these tests with caution. Having said that, they look promising in that they appear to perform well in suspect cases, particularly a subset of those that are relatively more severe. We have looked for evidence of this antibody in roughly 400 sera collected recently from people in this country without any suggestive evidence of SARS, and they're negative in all of those people.
If the indirect antibody test measures immune response to the virus (not sure, does anyone know?) it could be very useful for identifying recovered victims who no longer have the SARS virus in their bodies. This would be incredibly helpful because people whose immune systems have fought off the SARS virus could be used as blood donors to extract gamma globulin immune system molecules from their blood. The gamma globulin can be used to treat the most severe cases of SARS.
Whether SARS is eventually controlled continues to strike me as being heavily dependent on whether it reaches less developed places where the public health infrastructure is nearly non-existent. Let it get loose in India and it seems like it would become impossible to control.
A forthcoming New Scientist article reports the greatest fear of SARS (Severe Acute Respiratory Syndrome) researchers is the possibility of asymptomatic "silent carriers" may make SARS uncontainable
But if people can harbour and transmit the virus while while remaining healthy, or showing few symptoms, it will be much harder. "If there are silent carriers, it will be virtually impossible to contain," warns Osterhaus. This issue is now the focus of research, says Heymann. A lab test for SARS would give a huge boost to surveillance and containment efforts.
If the disease reaches India or some other country where few people have access to an organized healthcare infrastructure then the disease is going to be extremely difficult to contain anyhow. We could quickly reach a point where many countries stop allowing travel from countries where the disease is spreading unchecked.
Lucien Abenhaim, who as director-general for health is France's equivalent of surgeon-general, noted however "we know now that there are minor forms of the illness," meaning that people can be infected but have only minimal symptoms.
Hopefully the silent carrier fear will not pan out. But even if it doesn't it is by no means assured that SARS can be contained at this point.
SARS demonstrates the value of speedier methods to isolate and characterize pathogens. Technologies under development to make nanodots and other nanotech sensor approaches for biological material promise someday to speed up the development of defenses against new infectious agents by orders of magnitude. Advances in biotech are already evident in the response to SARS. It took many months to identify and characterize the cause of Legionnaire's Disease back in the 1970s. The pace of the advance in the SARS investigation has been much more rapid. The scientists working on the cause of SARS have already focused their attention on a coronavirus after an initial suspicion that a paramyxovirus might be the cause. Now scientists are reporting that SARS might have been come about from the mixing of DNA from coronaviruses from different mammalian species.
Canadian scientists racing to find the cause of SARS say it appears to be a mutant strain of coronavirus with bits of human, cow and mouse virus scrambled into its genetic code.
The likely way this happened was that a single animal or human was infected by human and animal coronavirus strains at the same time. Different kinds of coronavirues in the same cell swapped genes to create a new and more virulent hybrid. Separately, other scientists have shown that cross-species mixing of coronaviruses can create new and more infectious forms of virus.
Now, in a simple overnight experiment, researchers transformed a coronavirus that is lethal to cats into one that infects mouse cells by replacing a single gene1.
The genetic code of the coronavirus that is suspected of causing SARS is expected to be approximately 30,000 DNA base pairs in length. Scientists are working with isolates of the SARS coronavirus to sequence it. Once it has been refined into a pure enough form to be DNA sequenced the current equipment for DNA sequencing could read its code within a single day. However, sequencing is normally done several times to check for errors and so this process can take a week or two. Where we are still lagging in speed is in the ability to then develop a vaccine or drug that can counteract the effect of SARS. The best prospect for development of an anti-SARS treatment in the short term is in the isolation of gamma globulin from the blood of those who have recovered from the disease.
Although no drugs have proved useful in treating the viral infection, Dr. Leung Ping-chung of Prince of Wales Hospital said Monday that doctors used gamma globulin from recovered patients to treat 20 severely affected victims
The success of the gamma globulin treatment raises the prospects of being able to reduce SARS deaths in industrialized countries should SARS reach pandemic levels.
The rate of scientific progress in investigation of the cause of SARS might be fast enough to stop the spread of the disease because tests may be developed to speed its detection. Though that the containment of SARS is by no means assured. Even if we manage to dodge the bullet this time there is no reason for complacency. If an influenza (which is probably more easily transmissible) of equal or greater lethality was to pop up then the odds of containing it with current technology and current public health practices would be much lower. Therefore even in the industrialized countries humanity remains quite vulnerable to new and more lethal forms of natural pathogens.
The New Scientist has a worthwhile SARS theme page with all their SARS articles.
Update: You can find all of the FuturePundit SARS posts in the Natural Dangers category archive. Also, you'll find my coverage of the economic impacts of SARS on my ParaPundit blog in the Political Economics category archive
Update II: To clarify: Note that in the event of an outbreak of SARS into wider populations that while gamma globulin may be able to save many lives in industrialized countries SARS would exact a far higher toll in less developed countries. Also, as is being demonstrated in East Asia right now the economic consequences of a SARS pandemic would be enormous. I've been posting a lot on SARS because its like we are out there on the edge of a precipice and it is not yet clear whether we are going to take the plunge.
Reacting to the spread of the new infectious disease Severe Acute Respiratory Syndrome (SARS) the World Health Organization has advised against travel to Hong Kong and Guangdong province of China.
Wednesday, 2 April, 08:30 Palais des Nations
World Health Organization
Dr David Heymann, Executive Director, Communicable Diseases
Dr Guenael Rodier, Director, Communicable Disease Surveillance and Response
Mr Dick Thompson, Communications Officer
Mr Dick Thompson
This will be an abbreviated press briefing. You will have an opportunity to ask a few questions, but not many. The reason is that they are getting on a flight to attend Carlo Urbani's funeral in Italy.
Statement from Dr David Heymann
Good morning. Thank you for coming this morning. We have two different types of information to offer to you this morning. The first is that China is now a full partner with WHO. The teams have been asked to immediately go to Guangdong. Guangdong has reported the number of cases that have occurred during the month of March, which is 361 cases and 9 deaths, which mean that the epidemic is still going on in Guangdong, and they have promised that later today they will provide all of the information that they have obtained from their national disease surveillance system looking for SARS. So we are very pleased to announce that China is now a full partner with other international partners, in fact with the rest of the world, in collaborating on stopping this epidemic and in finding out the various aspects that we need to find out.
The second [type of information] is that since control measures have begun in Hong Kong, which began on 15 March, just after we made our announcement, and in other parts of the world, control measures have been successful in stopping the disease. For example, in Viet Nam the disease has been stopped we believe. In Singapore and Toronto, activities are going on and they are having good success.
I would like to focus now on Hong Kong, however, where since 15 March there have been 9 people, travellers, tourists or businessmen, from Beijing, from Taiwan, and from Singapore, who have returned home from Hong Kong infected with SARS. In addition in Hong Kong, they have found that transmission does not seem to be only by close contact from person to person. It appears that there is something in the environment that is transferring virus, which is serving as a vehicle to transfer the virus from one person to another. We do not believe this is the air. We believe that it is something else in the environment and we have talked about that in past press conferences. It is possibly an object that people are touching and getting infected from, where there has been a SARS patient who has coughed, or possibly a sewage system or a water system or some type of environmental vehicle that takes the virus from a sick person to others. So we see clusters of cases where there is one case, for example, living in an apartment building, where other people in that apartment building have been infected.
So for these two reasons, because of the fact that we do not completely understand the means of transmission in Hong Kong, and because since the 15 March tourists and businessmen have returned from Hong Kong to their countries with infection, we have decided to make a recommendation that people who are planning travel to both Hong Kong and Guangdong, which as you know is adjacent to Hong Kong, consider postponing their travel until another time. We will be working daily with the Hong Kong authorities, and we have daily conference calls with them and now we will begin also with Guangdong authorities, to determine if there are any reasons that we can stop that recommendation. In other words, the recommendation will be reevaluated every day and we will make a decision every day whether or not that needs to be changed. So now what we have is from all sites where there is a SARS outbreak that is causing chains of transmission, we have requested that tourists or travellers understand about the disease, that airports screen passengers who are returning to their countries from these sites, and now, in addition, we are telling travellers who are planning to go to Hong Kong and Guangdong that they consider postponing their travel. So what we have is a system in place now which will, we hope, stop the spread from the sites where SARS is occurring internationally and at the same time help passengers, tourists or businessmen who are planning to go to Hong Kong or Guangdong decide better whether or not they should go. We are recommending that they reconsider their travel plans and postpone if possible their travel to Hong Kong or Guangdong.
It is noteworthy that SARS has not been contained in China. The Chinese claimed they had it under control. Instead it has been spreading. China appears to finally be cooperating with the WHO. But the Chinese authorities have been quite irresponsible up to this point. The disease first showed up in Guangdong province China in November 2002. If the world's infectious disease experts had been notified at that time we'd be about 5 months further along in the learning curve about this disease and containment measures to stop international spread would have been begun much sooner and with much greater success.
Some countries are taking more drastic action. If travelling from Hong Kong to Thailand you will be placed in quarantine when you reach Thailand.
Q. Yes, Dr Heymann, can you explain a little bit about the process prior to issuing this advice? While it probably makes sense from the health perspective, it will have economic, social, political impact in the region. I’m wondering if you have consent from authorities in Guangdong, Hong Kong, or China?
A. Dr David Heymann: We’ve spoken first of all with IATA, which is the International Air Transport Association, and they have understood this and they have given their agreement that this is the recommendation which should be made at this point. We’ve discussed with the various different countries in the region, with our regional office and through our regional office, and we find that in those countries there are already much more strict recommendations than this is. For example, in Thailand, the government has announced that all returning passengers from Hong Kong will be quarantined. So we understand that there are very serious measures already being taken in many countries. So we made this decision with countries, with WHO and, more importantly, with our expert group of advisers on travel and health. We’ve spoken with many of our advisers, you know we have various advisers around the world, we have talked with them as well. And through all of these discussions, which went on all day yesterday and the day before, we’ve come to this conclusion.
The economic consequences of SARS could grow very large. Of course the tourist industry will be hit. But also various business meetings that facilitate international trade will not take place.
Update: This WHO recommendation is unprecedented. The World Health Organization has never before in its history totally recommended against travel to a specific geographic area.
This is the first time in the history of WHO that such travel advice has been issued for specific geographical areas because of an outbreak of an infectious disease.
Since 1958, WHO has issued weekly lists of areas infected with quarantinable diseases so that national authorities can decide whether to apply public health measures to arriving travellers. During the last years of the smallpox eradication campaign cases spread internationally by land. Controls at borders between neighbouring countries were relied on to prevent international spread. No global recommendations were necessary.
Here is the World Health Organization press release for the travel advisory: Update 17 - Travel advice - Hong Kong Special Administrative Region of China, and Guangdong Province, China
The SARS situation in Hong Kong Special Administrative Region has developed features of concern: a continuing and significant increase in cases with indications that SARS has spread beyond the initial focus in hospitals. These developments have suggested environmental routes of transmission from a SARS infected person which may be related to contamination of common systems that link rooms or flats together. Despite the implementation of strict measures to control the outbreak, there have continued to be a small number of visitors to Hong Kong who have been identified as SARS cases after their return from Hong Kong. The epidemic in Guangdong Province of China, situated adjacent to Hong Kong, is the largest outbreak of SARS reported and has also shown evidence of spread in the wider community. As a measure of precaution WHO is now recommending that persons travelling to Hong Kong and Guangdong Province of China consider postponing all but essential travel. This temporary recommendation will be reassessed in the light of the evolution of the epidemic in the areas currently indicated, and other areas of the world could become subject to similar recommendations if the situation demands.
Please note that this recommendation applies only to travellers entering Hong Kong Special Administrative Region of China and Guangdong Province of China, not to passengers directly transiting through international airports within those areas.
Initially when the new infectious disease SARS (Severe Acute Respiratory Syndrome) emerged early indicators were that it was not easily transmissible. The first indication that it might be more easily transmitted was the discovery of its transmission from one doctor to several people who stayed on the same floor of the Metropole Hotel in Hong Kong. As SARS continues to spread a consensus is emerging that SARS is much more easily transmissible than originally thought. Suspicions that it is caused by a coronavirus strengthen this belief because about one third of all colds are caused by coronaviruses and of course colds are fairly easily transmitted.
The Hong Kong Department of Health has today issued an unprecedented isolation order to prevent the further spread of Severe Acute Respiratory Syndrome (SADS). The isolation order requires residents of Block E of Amoy Garden to remain in their flats until midnight on 9 April.
The decision to issue the isolation order was made following a continued steep rise in the number of SARS cases detected in the building over the past few days. Concern about a possible outbreak in Amoy Garden mounted on Saturday, when 22 of Hong Kong’s 45 new SAR cases hospitalized that day were determined to be residents of the estate. On Sunday, 36 of the 60 new patients admitted to hospital with probable SARS were Amoy Garden residents.
Hong Kong health authorities today informed the public that a cumulative total of 213 residents of Amoy Garden had been admitted to hospital with suspected SARS since reporting on the disease began. Hong Kong’s outbreak began on 12 March when health officials first recognized a cluster of cases of atypical pneumonia in the Prince of Wales Hospital.
Of the 213 Amoy residents affected in the outbreak, 107 patients resided in Block E. In addition, most of these 107 patients from Block E lived in flats that were vertically arranged.
This suggests that SARS may be spreading in Hong Kong according to a different pattern, still involving close person-to-person contact with bodily secretions from an infected person. WHO epidemiologists are considering the possibility that bodily secretions containing the causative virus might somehow enter common systems that link rooms or flats together. This pattern of spread would be in addition to the well-documented face-to-face contact that has been seen in the majority of cases reported so far.
Earlier this month, Hong Kong epidemiologists detected an unusual pattern of transmission among guests and visitors at the Metropole Hotel during the critical period of 15 to 23 February. Guests and visitors at a single floor of the hotel are thought to have spread SARS to Toronto and Singapore and to have started the outbreak in Hong Kong’s Prince of Wales Hospital. No staff at the hotel developed symptoms
The guests of the Metropole Hotel who got SARS all stayed on the same floor of the hotel. This again suggests spread of the disease via air ducts.
If ducts in the Amoy Garden building are spreading SARS then quarantining the people of that apartment building and forcing them to stay inside may well turn out to be a death sentence for some of them. The ones who are not yet infected will be forced to remain close to those who are infected but not yet diagnosed. Therefore the spread of the disease within Amoy Garden may continue.
If the disease continues to spread and more quarantines are ordered then it is quite possible that people will resist being quarantined in close quarters with other people who might be infected. The Amoy Garden quarantine is already being enforced by police stationed outside to prevent people from entering or leaving.
The Hong Kong housing block, the Amoy Gardens in Kowloon, was surrounded by about 50 police officers on Monday, as the Hong Kong authorities invoked quarantine laws to try to stem the growing crisis.
In a really large scale outbreak there would not be sufficient numbers of police available to enforce quarantines. If the connection between SARS spread and air ducts is established then in the event of a large scale outbreak many people will likely flee from multi-unit dwellings such as apartment buildings.
While SARS spread on a single floor in the Metropole Hotel the pattern of SARS spread in the Kowloon apartment block is different
"They are finding that the infections are in people living in apartments on top of each other, only in one area of this apartment block. It's only two apartments, but from floor zero to 35. Not all of those apartments are affected, but most of the families affected are living in that small area of that apartment building," virologist Klaus Stohr said at WHO headquarters in Geneva.
One potential explanation for the difference in the pattern of spread in the Metropole Hotel and the Amoy Garden may be a different duct work layout. Ducts might be laid out in a more columnar structure in the Amoy Garden and more in rows in the Metropole.
If, as suspected, SARS is caused by a previously unidentified member of the coronavirus family then it is probably similar to other coronaviruses and possesses the ability to survive on exposed surfaces for a few hours at least. Therefore it might be transmissible by touching a surface at a location where an infected person coughed a few hours previously. Frequent handwashing may help to reduce its spread.
By the end of March 2003 there have been 1622 reported cases of SARS and 58 deaths. That is a nearly 4% death rate. But the actual death rate is likely even higher since some of the currently infected out of the 1622 will eventually die from the infection.
While most types of influenza tend to kill only the very old, the very young, and those who are immuno-compromised SARS kills people in the prime of life.
Dr. Carlo Urbani, an expert on communicable diseases, died today of SARS. Dr. Urbani, worked in public health programs in Cambodia, Laos and Viet Nam. He was based in Hanoi, Viet Nam. Dr. Urbani was 46.
The great influenza pandemic of 1918-1919 (popularly known as the Spanish Flu) also struck down those in the prime of life. Though while Spanish Flu caused the highest mortality rate in those aged 20-39 WHO official Mark Salter says the risks of dying from SARS are greater for those over 40 years old.
Age could be one factor, with people over 40 apparently at greater risk, while the fact that a patient was already suffering from some other chronic ailment, such as heart or liver disease, could also play a part, he said. "The indications seem to be that if the patient is over the age of 40 and has other illnesses as well...they would be more prone to developing a more severe form when the chances of survival become smaller," he told Reuters.
Here are excerpts of the March 29, 2003 CDC press conference held by CDC director Dr. Julia Gerberding. (bold emphases added)
We believe, based on what the investigations have shown us so far, that the major mode of transmission still is through droplet spread when an infected person coughs or sneezes and droplets are spread to a nearby contact. But we are concerned about the possibility of airborne transmission across broader areas and also the possibility that objects that become contaminated in the environment could serve as modes of spread.
Coronaviruses can survive in the environment for up to two or three hours ,and so it's possible that a contaminated object could serve as a vehicle for transfer to someone else.
In health care settings, we have already initiated guidance to protect against droplets, airborne and contact spread of this virus, and today we're issuing an update on how to protect people in homes of SARS patients.
We know that the individual with SARS can be very infectious during the symptomatic phase of the illness. We don't know how long the period of contagion lasts once they recover from the illness and we don't know whether or not they can spread the virus before they have the full-blown form syndrome.
But most of the information that the epidemiologists have been able to put together suggests that the period of contagion may begin with the onset of the very earliest symptoms of a viral infection, so our guidance is based on this assumption.
About one third of all common cold infections are caused by a type of coronavirus. Hence Dr. Gerberding makes a comparison to cold virus spread.
DR. GERBERDING: We are very vigilant about the possibility of spread. We recognize that there are at least some patients with SARS that are extremely efficient transmitters. We don't know to what extent all patients are particularly infectious but there are clearly some who appear to be very highly infectious, and, for example, in Hanoi where there was one patient who was a source for health care worker transmission and approximately 56 percent of the health care who had direct contact with the patient appeared to have acquired SARS.
So given that high degree of contagion and what we know about spread of cold viruses, I think we are very alert to the possibility that this could spread outside of the confined populations that I've mentioned, travelers to the affected areas, close household contacts, and health care workers. But we are not seeing that now and we are looking for it very closely.
So if we begin to appreciate that, we will have to expand our recommendations to be more inclusive of special protective measures for contacts.
The biggest danger is that SARS is spreading in places that are effectively out of sight of Western investigators. The most likely country where SARS is still spreading is China. Western disease experts still have very little visibility into what is really happening with SARS spread in China.
DR. GERBERDING: Well, from the standpoint of CDC, I would say that we are very concerned about the spread of this virus, particularly in Asia. We recognize this as a epidemic that's evolving differently, in different geographies, but nevertheless, it is a respiratory virus, it does appear to be transmitted very efficiently, and what we know about respiratory viruses suggests that the potential for infecting large numbers of people is very great.
So we may be in the very early stages of what could be a much larger problem as we go forward in time. On the other hand, this is new, we don't know everything about it, and we have a lot of questions about the overall spread.
The patterns of transmission in the individual countries vary, depending on where the primary foci of transmission is occurring.
In Hong Kong, the situation is particularly alarming because we have several hospitals that are affected, and there are so many health care workers in each of these hospitals that could have been exposed or who are developing SARS, that there's already a multiplier in the community. Every health care worker has household contacts, those contacts, when they become ill, have had other exposures.
So we are very concerned about the speed and the amplification process in Hong Kong. On the other hand, the health officials there are taking extremely efficient and aggressive steps at this point in time to contain spread in that community, including closing schools and closing hospitals, and cohorting health care workers and patients.
So it remains to be seen whether or not those measures will attenuate the spread. The biggest unknown is of course what is going on in China and we are desperate to learn more about the scope and magnitude of the problem there, because that really I think will be the biggest predictor for where this will be headed over the next few weeks.
Here we are over 5 months after the SARS disease first surfaced in China and CDC and WHO authorities still know little about how the disease developed and spread in China. As a consequence of our ignorance of the disease's spread in China we have only the information developed from the course of its much more recent appearance in Hong Kong and in places outside of China. Therefore we simply do not yet know enough to say what are all the ways by which SARS can be transmitted.
Concerns that I mentioned earlier focused on droplet transmission, so if you were in the elevator and an infectious person literally coughed on you, it's conceivable that you could acquire a respiratory infection, including SARS, through that mechanism.
On the other hand, most of the information suggests that fairly prolonged contact, on a face to face basis, is typical of the transmissions.
There are anecdotal reports, that we haven't confirmed yet, of much briefer contact. There's been a concern expressed about the potential for airborne or surface contamination in the apartment in Hong Kong, and these are all open questions that we are aggressively pursuing here.
It could be worse. A moderately severe influenza strain (i.e. not as bad as the 1918 outbreak but worse than the average influenza strain) has a higher mortality rate than SARS. Though influenza tends to take the very young and very old and hence elicits less fear in the general population.
DR. GERBERDING: Certainly, there could be other cofactors involved such as viruses or underlying illness, but this is just atypical pattern for any infectious disease. If you get pneumococcal infection, many people have completely asymptomatic. Some people get a mild disease and some people have a full blown, very, very severe illness from the infection.
So this is a typical pattern for respiratory illnesses, not something that we're surprised about. In fact if there's any good news in SARS right now, it's that the majority of patients do appear to recover and that the death rate is actually lower than what we see with epidemic influenza, about 3.5 percent of the patients have died from the illness. That is still a tragic occurrence for the people who are affected, and their families, and I would never mean to minimize it. But it is fortunate that it is not even more severe.
The real tragedy in the case of SARS is that the Chinese government has managed to make a bad situation worse. In spite of the fact that SARS first surfaced in China in November 2002 the rest of the world did not hear about it until it started causing infections in Hong Kong and Vietnam a few months later. The irresponsibility of the Chinese government may lead to a massive outbreak throughout the world.
The president of Taiwan, which has 10 cases of Severe Acute Respiratory Syndrome (SARS), has been the most outspoken. "SARS first broke out on the Chinese mainland, but the authorities covered up the information, leading to a global epidemic," Chen Shui-bian said on Friday. China initially admitted to five deaths, but a toll of 31, and 800 infections, since November was revealed on Wednesday.
The press in China is highly controlled and is not a reliable source of information about the extent of SARS in China. Also, the Chinese government has resisted providing the WHO much information about SARS. On Friday March 28 2003, over 5 months after SARS first showed up in China, the Chinese government finally agreed to allow WHO disease experts access to Chinese information about SARS infections in China. But it is far from certain that China will be completely forthcoming. One international health official quoted off-the-record in the article above says that the disease is probably far more widespread in China than the government of China is admitting to even now. There are parts of China that are poor where most of the population have little access to health care services. Even if the most developed countries take steps to slow the spread of SARS at this point it seems likely that SARS will spread in less developed countries.
If China had reported its SARS outbreak back in November of 2002 we'd be about 4 or 5 months further along in developing tests, developing vaccines, studying its mode of transmission, and developing ways to minimize its spread. But the Chinese government instead hushed it up and the result may eventually be millions of deaths that could have been avoided.
What to do to avoid becoming infected? Face masks may not help that much.
Doctors say sick people who put on masks become less likely to transmit the illness when they cough or sneeze. But it is unclear whether the masks help the healthy. They quickly become saturated with moisture from breath and lose some usefulness when worn for hours - much less for days, as is happening here now - local doctors warn.
We really need to know more about the efficacy of facial masks for blocking SARS' spread. If it looks like SARS is going to spread into the general population keep in mind that protecting the eyes from airborne droplets might also be of some value for reducing risks. Goggles or safety glasses might reduce the risks of transmission. Also, frequent hand washing when out in public places may also reduce the risks of getting the illness.
One big question in my mind is about how duct work and air filters are laid out in large buildings. Do most buildings do a good job of filtering out particles from air that comes out of each dwelling or office before that air passes into other areas in the same building? Also, could air filters be rapidly placed into existing buildings to reduce the spread of airborne virus particles? If people begin to fear living and working in large buildings the economic costs of the fear of SARS could become enormous very quickly.
If SARS breaks out into the general population the fatality rate may rise. Currently because so few people have SARS each person can receive a great deal of care including respirators when necessary. But if large numbers of people become infected there will not be enough equipment or medical workers to care for them.
SARS may cause an enormous economic impact. If the fear of SARS grows large enough then many people will avoid both business and personal travel, restaurants, movie theaters, shopping malls, and other public places with large numbers of people. Consumer demand will therefore decline and the rate at which business deals are negotiated will slow.
Also see my previous posts on SARS: Severe Acute Respiratory Syndrome Causing Concerns and Hunt For Cause Of Severe Acute Respiratory Syndrome.
But coronaviruses are prone to transformation. They have an unusually large amount of genetic material, as well as enzymes that enable them to shuffle it. A new, more virulent mutant could easily result.
American Airlines Flight 128 from Tokyo is being held on the tarmac at San Jose International Airport after two passengers and two crew members complained of feeling unwell, airport officials said.
People will become more afraid to fly if SARS continues to spread. Also, if many flights get quarantined there will even be a reduction in the number of flight crews available to fly aircraft.
Some airlines in the Southeast Asian region are moving to reduce the risk of infection. Thai Airways International and other airlines of Thailand are requiring passengers from high risk countries (Singapore, Hong Kong, China, Taiwan and Vietnam) to wear surgical masks.
Here's some more bad news about surgical masks. Australian expert David Bromwich says surgical masks do not provide much protection against airborne disease.
But David Bromwich, an expert in respiratory protection from Brisbane's Griffith University, said that passengers wearing surgical masks to guard against respiratory disease were "kidding themselves". Dr Bromwich said surgical masks were originally designed to stop transmission of saliva from doctor to patient, but offered almost no protection from tiny airborne disease particles. "It's a false sense of security," he said.
Since surgical masks do not provide much benefit I guess it doesn't matter that there is an enormous surgical face mask shortage developing. The 3M plant for manufacturing N95 surgical masks is operating at maximum capacity and can not keep up with demand.
The masks, made of a micro-fibre designed to filter out impurities, are manufactured at a plant in the United States, currently operating 24 hours a day under a "state of emergency."
Canada, which has been much harder hit by SARS than the US faces a surgical mask shortage for medical workers.
Hong Kong just reported a new single day record of 75 new cases of SARS diagnosed and other countries are reporting new cases. These cases are spurring countries in the region most hard hit by this new disease to take increasingly stringent measures to stop the spread of SARS.
Hong Kong invoked a colonial-era law Tuesday to quarantine more than 240 people in countryside vacation camps, part of redoubled efforts to halt the spread of a mysterious flu-like illness that has killed at least 63 people around the world.
The 240 are all from block E of the Amoy Garden apartment building complex.
SARS has so far killed about 3 to 4 per cent of the 1500 sufferers. But be thankful it is not as infectious as common influenza.
"If it were flu, it would be all over the world with millions of people infected," says Victoria's public health chief, Dr Robert Hall.
The containment of SARS has been found to be quite difficult for public health authorities and success is by no means assured. There is a lesson here: If a more easily transmittable disease of equal or greater lethality emerged then unless the threat it posed was recognized at a very early stage and attempts to stop its spread were very aggressive it is unlikely that it could be contained.
Tired of the war? Not sufficiently scared by the spread of SARS? What something different, more dramatic, and larger scale to worry about? How about the running down of the nuclear reactor supposedly at the Earth's core?
Geophysicist J. Marvin Herndon argues that the core of the Earth is really a 5 mile (or 8 kilometer) uranium ball that operates as a natural nuclear reactor. He says some day the reactor will exhaust its supply of radioactive material and that when it does the Earth's magnetic field will collapse with disastrous consequences.
SAN DIEGO, March 27 (UPI) -- New government laboratory test results are fueling a controversial contention that a giant natural nuclear reactor at the center of the Earth powers the planet's life-protecting magnetic field -- but it might be running out of gas, scientists told United Press International.
Herndon happens also to have served as a technical consultant for the new disaster movie "The Core" which is based on the idea that the Earth's core will stop spinning.
J. Marvin Herndon of Transdyne Corp. in San Diego, who worked as an advisor to Paramount Pictures in the creation of the new science thriller, maintains that a nuclear "georeactor" provides most of the heat in the Earth's spinning core
Unfortunately its probably impossible for real life terranauts to travel down to the Earth's core and fix it if the core starts running out of nuclear fuel.
A new research paper published in the Proceedings of the National Academy of Sciences provides supporting evidence for the theory.
Computer simulations of a nuclear reactor in the Earth's core, conducted at the prestigious Oak Ridge National Laboratory, reveal evidence, in the form of helium fission products, which indicates that the end of the georeactor lifetime may be approaching.
Dr. Fred Vine laid the foundations for many of Herndon's theories in the 1970s. Vine, however, believes that the Earth's core stops spinning every 400,000 years.
The August 2002 issue of Discover has a fairly lengthy write-up of Herndon's theory.
In Herndon's view, these polarity flip-flops make no sense if the magnetic field is powered, as traditionalists contend, by heat from the crystallization of molten iron and nickel from the fluid core or from the decay of isolated radioactive isotopes. "Those are both gradual, one-way processes," he says. But if the field's energy results from a mass of uranium and plutonium acting like a natural nuclear reactor, Herndon says, such variations in the field's strength would be almost mandatory.
"It's a self-sustaining critical reaction," said nuclear engineer Daniel F. Hollenbach of Oak Ridge National Laboratory, a longtime collaborator of Herndon's until the two parted ways last year. "Depending on how much it fissions, that's the power."
There are a few separate issues here. One is whether the Earth's core is a large nuclear reactor that drives the Earth's magnetic field. There is no consensus among geophysicists that this is the case. Herndon is definitely in a small minority with his theory. However, there is also the widely accepted theory that every few hundred thousand years the Earth's core stops spinning, the magnetic field collapses, and then the core starts spinning again and the magnetic field reverses. So a magnetic field collapse could still happen as part of the process of periodic magnetic field collapse even if Herndon's theory is wrong.
This leads to the important question: Could the Earth's magnetic field reverse today? The British Geological Survey weighs in on the odds of the possibility.
Measurements have been made of the Earth's magnetic field more or less continuously since about 1840. Some measurements even go back to the 1500s, for example at Greenwich in London. If we look at the trend in the strength of the magnetic field over this time (for example the so-called 'dipole moment' shown in the graph below) we can see a downward trend. Indeed projecting this forward in time would suggest zero dipole moment in about 1500-1600 years time. This is one reason why some people believe the field may be in the early stages of a reversal. We also know from studies of the magnetisation of minerals in ancient clay pots that the Earth's magnetic field was approximately twice as strong in Roman times as it is now.
Even so, the current strength of the magnetic field is as high as it has been in the last 50,000 years, even if it is nearly 800,000 years since the last reversal. Also, bearing in mind what we said about 'excursions' above, and knowing what we do about the properties of mathematical models of the magnetic field, it is far from clear we can easily extrapolate to 1500 years hence.
The British Geological Survey does not see a big threat to human life if an Earth's magnetic field reversal should start happening in earnest today.
Is there any danger to life?
Almost certainly not. The Earth's magnetic field is contained within a region of space, known as the magnetosphere, by the action of the solar wind. The magnetosphere deflects many, but not all, of the high-energy particles that flow from the Sun in the solar wind and from other sources in the galaxy. Sometimes the Sun is particularly active, for example when there are many sunspots, and it may send clouds of high-energy particles in the direction of the Earth. During such solar 'flares' and 'coronal mass ejections', astronauts in Earth orbit may need extra shelter to avoid higher doses of radiation. Therefore we know that the Earth's magnetic field offers only some, rather than complete, resistance to particle radiation from space. Indeed high-energy particles can actually be accelerated within the magnetosphere.
At the Earth's surface, the atmosphere acts as an extra blanket to stop all but the most energetic of the solar and galactic radiation. In the absence of a magnetic field, the atmosphere would still stop most of the radiation. Indeed the atmosphere shields us from high-energy radiation as effectively as a concrete layer some 13 feet thick.
Human beings have been on the Earth for a number of million years, during which there have been many reversals, and there is no obvious correlation between human development and reversals. Similarly, reversal patterns do not match patterns in species extinction during geological history.
The fact that Earth's atmosphere provides as much protection from radiation as 13 feet of concrete has interesting ramifications for space exploration and planet colonization. The ability to create a thick atmosphere on Mars would be enormously valuable not just for allowing people to go out and breath the atmosphere. It also greatly reduce the amount of radiation Mars colonists would be exposed to.
You can read more about Herndon's nuclear core theory and its ramifications on the NuclearPlanet website.
What have we done to anger the Sun God? Helios is getting hotter every decade.
Since the late 1970s, the amount of solar radiation the sun emits, during times of quiet sunspot activity, has increased by nearly .05 percent per decade, according to a NASA funded study.
"This trend is important because, if sustained over many decades, it could cause significant climate change," said Richard Willson, a researcher affiliated with NASA's Goddard Institute for Space Studies and Columbia University's Earth Institute, New York. He is the lead author of the study recently published in Geophysical Research Letters.
"Historical records of solar activity indicate that solar radiation has been increasing since the late 19th century. If a trend, comparable to the one found in this study, persisted throughout the 20th century, it would have provided a significant component of the global warming the Intergovernmental Panel on Climate Change reports to have occurred over the past 100 years," he said.
NASA's Earth Science Enterprise funded this research as part of its mission to understand and protect our home planet by studying the primary causes of climate variability, including trends in solar radiation that may be a factor in global climate change.
The solar cycle occurs approximately every 11 years when the sun undergoes a period of increased magnetic and sunspot activity called the "solar maximum," followed by a quiet period called the "solar minimum."
Although the inferred increase of solar irradiance in 24 years, about 0.1 percent, is not enough to cause notable climate change, the trend would be important if maintained for a century or more. Satellite observations of total solar irradiance have obtained a long enough record (over 24 years) to begin looking for this effect.
Total Solar Irradiance (TSI) is the radiant energy received by the Earth from the sun, over all wavelengths, outside the atmosphere. TSI interaction with the Earth's atmosphere,oceans and landmasses is the biggest factor determining our climate. To put it into perspective, decreases in TSI of 0.2 percent occur during the weeklong passage of large sunspot groups across our side of the sun. These changes are relatively insignificant compared to the sun's total output of energy, yet equivalent to all the energy that mankind uses in a year. According to Willson, small variations, like the one found in this study, if sustained over many decades, could have significant climate effects.
Perhaps we have gradually been angering the god Helios (a.k.a. Sol Invictus, Mithra, Ra, Dazhbog, and assorted other names for Sun and Light gods. Perhaps Helios is getting hotter under the collar as his anger builds.
Of course our prehistoric ancestors might intentionally have set out to do something that would gradually increase anger of Helios and to make him hot under the proverbial collar because they were freezing their buns in the Ice Age. Helios, being a God, may not react in the same time frame in which ephemeral mortals respond.
The Scientist web site has a good article on the hunt for the cause of SARS. The web site requires registration to access its articles but the registration is free and the site has generally good quality articles. Donald Lowe, head of the Department of Microbiology at Mount Sinai Hospital in Toronto thinks the hunt for the cause will succeed rather more quickly than similar hunts in the past.
But it took six months to identify the Legionella pneumophila bacterium as the cause of Legionnaire's disease, the pneumonia that attacked an old soldiers' convention in Philadelphia in 1976. Could it take just as long to identify the cause of SARS?
Unlikely, Lowe thinks. "Since Legionella, the molecular world has changed dramatically — if we have any evidence of an infectious particle, we can amplify the DNA or RNA, sequence it, and therefore be able more rapidly and accurately to define an agent. Unless we are dealing with a virus which is difficult to grow."
The New Scientist reports that a Canadian lab has ruled out 250 types of pathogens by testing samples from Canadian SARS victims.
Teams in Hong Kong and Germany said they had found evidence of a virus known as a paramyxovirus in at least some of the patients with the illness, called severe acute respiratory syndrome.
They stressed that more tests are needed before the virus is pinned down as the culprit, but said it is the best clue yet about the cause of the syndrome, which may have killed as many as 14 people and sickened hundreds more.
One of the Hong Kong scientists involved in the search for the pathogen is confident that his group has isolated the virus and that it looks like a paramyxovirus.
"We've identified the virus," said Dr. John Tam, a microbiologist at the Chinese University of Hong Kong, at a news conference late Tuesday. "We used an electronic microscope and found the virus in patient samples."
John Oxford, professor of Virology at Queen Mary's School of Medicine, said a similar virus had been discovered in Holland last year.
"It is rather slow-moving, rather restricted to families and hospitals, not a rip-roaring affair, but still very nasty.
Viruses in the Paramyxoviridae family include many common, well-known agents associated with respiratory infections, such as respiratory syncytial virus, and childhood illnesses, including the viruses that cause mumps and measles. Some of these viruses are widespread, particularly during the winter season. Screening of specimens could therefore be expected to detect particles of these common viruses. At this point, it cannot be ruled out entirely that tests for the SARS agent are detecting such “background” viruses rather than the true causative agent.
The Paramyxoviridae family also includes two recently recognized pathogens, Hendra virus and Nipah virus. These related viruses are unusual in the family in that they can infect and cause potentially fatal disease in a number of animal hosts, including humans. Most other viruses in the family tend to infect a single animal species only.
Nipah virus first began to cause deaths in humans in Peninsular Malaysia in 1998 in persons in close contact with pigs. The outbreak caused 265 cases of human encephalitis, including 105 deaths. Two separate outbreaks of Hendra virus, associated with severe respiratory disease in horses, caused two human deaths in Australia in 1994 and 1995. No human-to-human transmission was documented in either outbreak. No treatment was available for cases caused by either of these two viruses. Human-to-human transmission did not occur.
Even if the virus seen by the Hong Kong and German scientists via electron microscope is the infectious agent causing this disease and is from the paramyxoviridae family of viruses it is probably a previously unknown pathogen and not one of the known existing members of the paramyxoviridae family.
Still, Dr. Klaus Stöhr, a virologist and epidemiologist who is leading the health organization's scientific team investigating the illness, said that none of those viruses had caused a disease like the one under investigation, which doctors are calling severe acute respiratory syndrome, or SARS. Instead, the findings suggest that the virus might be a hitherto unknown member of the paramyxoviridae family.
If the SARS illness is positively identified as being caused by the paramyxovirus which the Hong Kong and German researchers have isolated then the only existing antiviral drug that might work against it is Ribavirin. Anti-viral drug development historically has been much more difficult than anti-microbial drug development. To date vaccines have been far more effective than anti-virals and this is likely to continue to be the case (though HIV is an exception to this pattern since HIV vaccine development has proven so hard to do). Other viruses of the paramyxoviridae family include measles and mumps and of course vaccines do exist for them. It therefore seems reasonable to expect that if the SARS illness is being caused by paramyxovirus the development of a vaccine should be possible.
Drug development time and vaccine development time are both usually measured in years. An exception to this is influenza. For influenza every year vaccines for new strains are usually developed within months of when the new strains are first detected. However, if this SARS pathogen is a paramyxovirus it is probably a species unknown to scientists and perhaps even from a genus heretofore unknown. Therefore developing a vaccine for it will require a lot more work to first understand it to a level of detail that would make vaccine development possible.
In the short to medium term the best line of defense against the SARS pathogen is likely to remain the rapid isolation of its victims. But the work to isolate and identify the virus is important because it will lead to tests for its presence. The ability to test and detect it will lead to a much more rapid ability to identify and isolate those who are infected by the virus. That, in turn, will help to prevent its spread. Therefore the race going on to identify and characterize the SARS pathogen could lead to a fairly rapid benefit for the public health.
Update: The SARS illness spread from China. It started there in November 2002. The Chinese government was very irresponsible for not telling the rest of the world about the illness until after it had spread to outside of China.
Although the outbreak in Guangdong province started in November, health officials said almost nothing publicly for months afterward. Chinese officials gave their first report of the outbreak in Guangdong province to the World Health Organization on Sunday, saying that the outbreak was abating on its own. The report raised hopes at the World Health Organization that it would burn itself out elsewhere as well.
Because millions of poor Chinese people live in close proximity with chickens and pigs new strains of influenza sometimes jump across from other species into humans. These strains have a much greater potential to be very virulent in humans than the strains that emerge from within the human population. Therefore China is the most probable origin of an influenza whose lethality could rival the so-called Spanish flu of the 1918 pandemic. For China to be slow about notifying the rest of the world about a newly emerging illness is therefore an extremely dangerous practice. Governments and public health officials around the world should be sharply critical of China's lapse in its responsibility in this matter.
Update III: The extent of the Chinese government's irresponsibility in failing to inform the rest of the world of the emergence of the SARS disease before it escaped from Guangdong province China is brought into sharp relief by the revelation of how SARS disease crossed over into Hong Kong. The carrier is now believed to have been a Guangdong doctor aged 64 who stayed in a Hong Kong hotel and infected 6 other people staying on the same floor of the hotel.
Director Margaret Chan said the source of the outbreak appeared to be a Guangzhou doctor who stayed at the Metropole Hotel in Waterloo Road last month and infected six others.
Had the Hong Kong medical establishment been properly informed of the threat it is very likely that hospitals would have been operating with a far higher degree of caution when examining new admittees and those who became ill with this disease would have been diagnosed and isolated much more rapidly. The Chinese government deserves a a serious loud dose of criticism for its handling of this matter.
Update IV: SARS is now suspected of being caused by a coronavirus. Blood serum from recovered victims has had gamma globulin extracted from it and injected into the bodies of those with very severe SARS and the gamma globulin treatments have been very effective in treating severe cases of SARS.
"Facts have proven that in at least 20 of our patients who went through very smooth recovery, their serum has been used to treat very severe sufferers and that has been very successful," said Leung Ping-chung, a professor and surgeon at the Prince of Wales Hospital in Hong Kong, considered ground zero of the outbreak.
Also see my more recent post Fears Grow That SARS May Spread Into Pandemic.
The idea that asteroids as small as 100 meters across pose a serious threat to humanity because they create great, destructive ocean waves, or tsunamis, every few hundred years was suggested in 1993 at a UA-hosted asteroids hazards meeting in Tucson.
At that meeting, a distinguished Leiden Observatory astrophysicist named J. Mayo Greenberg, who since has died, countered that people living below sea level in the Netherlands for the past millennium had not experienced such tsunamis every 250 years as the theory predicted, Melosh noted.
But scientists at the time either didn't follow up or they didn't listen, Melosh added.
While on sabbatical in Amsterdam in 1996, Melosh checked with Dutch geologists who had drilled to basement rock in the Rhine River delta, a geologic record of the past 10,000 years. That record shows only one large tsunami at 7,000 years ago, the Dutch scientists said, but it coincides perfectly in time to a giant landslide off the coast of Norway and is not the result of an asteroid-ocean impact.
In addition, Melosh was highly skeptical of estimates that project small asteroids will generate waves that grow to a thousand meters or higher in a 4,000-meter deep ocean.
Concerned that such doubtful information was -- and is -- being used to justify proposed science projects, Melosh has argued that the hazard of small asteroid-ocean impacts is greatly exaggerated.
Melosh mentioned it at a seminar he gave at the Scripps Institution of Oceanography a few years ago, which is where he met tsunami expert William Van Dorn.
Van Dorn, who lives in San Diego, had been commissioned in 1968 by the U.S. Office of Naval Research to summarize several decades of research into the hazard posed by waves generated by nuclear explosions. The research included 1965-66 experiments that measured wave run-up from blasts of up to 10,000 pounds of TNT in Mono Lake, Calif.
The experiments indeed proved that wave run-up from explosion waves produced either by bombs or bolides (meteors) is much smaller relative to run-up of tsunami waves, Van Dorn said in the report. "As most of the energy is dissipated before the waves reach the shoreline, it is evident that no catastrophe of damage by flooding can result from explosion waves as initially feared," he concluded.
The discovery that explosion waves or large impact-generated waves will break on the outer continental shelf and produce little onshore damage is a phenomenon known in the defense community as the "Van Dorn effect."
But Van Dorn was not authorized to release his 173-page report when he and Melosh met in 1995.
The asteroid that exploded over the Tunguska River in 1908 is estimated to have been 160- to 180-feet in diameter. And a similar sized asteroid is believed to have exploded over Khazakstan in the late 1940s.
The 1908 Tunguska Siberia asteroid was fairly small and yet devastated a large area when it exploded.
A notorious example occurred in 1908 when an asteroid in this size range is believed to have exploded above the uninhabited Tunguska region of Siberia, leveling trees for some 800 square miles (2,000 square kilometers) around. Astronomers have for a decade or so said so-called Tunguska events probably occur about once every hundred years, leading some to speculate that we're about due for another.
So the take-home lesson is that you can still worry about getting killed by smaller asteriods that could hit closer to where you are. You just can't expect to be killed by a sub-kilometer asteroid that hits the ocean thousands of miles away from land.
Update VII: SARS now looks to be much more infectious than previously thought. See my later post Fears Grow That SARS May Spread Into Pandemic. Also read below for historical context about previous epidemics.
There is a new deadly strain of some kind of pathogen (its not yet clear if its an influenza but it is suspected to be a virus of some kind) has been making some people sick and it appears to have originated in Guangdong province China. The illness is being called atypical pneumonia or Severe Acute Respiratory Syndrome (SARS). The nature of the illness has started to raise alarms.
Before we get to that lets put it in perspective by taking a brief look at most famous and deadly influenza outbreak recorded in modern history. The lethality of that outbreak explains why public health officials become very worried when new strains of pathogens with increased lethality are reported.
The Epidemic spread quickly around the earth. In all, some 525 million people were infected by the virus, with about 21 million people dying. That was more than twice the number who had been killed during the Great War. In many countries public gatherings were forbidden. The Flu was especially devastating on many people as they welcomed back their men from the war, overjoyed that they had managed to survive the slaughter that was the war. But their joy soon turned to grief when they found out that their men had brought the virus back with them, and it would not only kill them but also other family members.
The flu may really have originated in Tibet but the first known concentration of deaths from it occurred in Spain and hence its called the Spanish Flu. The estimates of how many died from it vary from 20 to 40 million. Spanish Flu struck down people in the prime of life.
Spanish Influenza swept the entire globe in the years 1918-1920, leaving a billion people sick, more than half of the worid's population at that time. It killed at least 30 million people, threc times the death toll of World War l (Wilton 1993). A study for Norway has recently resulted in an upward revision of the death toll. The suggested estimate is 14 676, twice as high as the most frequently cited figure (Mamelund 199Sa). The socio-economic impact of the flu was also considerable. One reason for this is that the flu took its greatest toll among people in their most productive ages (20-40 years, especially men), i.e. that part of life when people tend to marry and have children (Mamelund 1998a).
The 1918 Spanish flu was one of the most contagious viruses ever known. It killed as many as 40 million people in the winter of 1918 and 1919, more than died in the First World War.
Flu strains vary considerably in their lethality. Spanish flu belongs to the Type A strain. Type A strains are usually more lethal than other types. See here and here for information about influenza types and how they mutate to form new strains. A later type A influenza strain killed hundrends of thousands in 1968:
Hong Kong Flu - Common name for the influenza A strain that killed nearly 750,000 people around the world in the 1968 pandemic
Influenza mutates. Some mutations are more lethal than others. As Spanish flu demonstrated, some can be incredibly lethal. Should we be worried that a new influenza strain might pop up and kill millions including members of our families and circles of friends? Well, on one hand we have more advanced medical technologies. You might think we could much better handle a new strain that was as harmful as the Spanish flu. But keep in mind that if a significant portion of the population gets sick all the hospital beds will fill up and there won't be enough respiratories and other modern medical equipment to go around. Also, we don't have highly effective treatments to use against viruses that compare to the antibiotic drugs that are effective for use against most bacteria (though the rise of drug resistant bacterial strains is making bacterial infections a growing concern).
Another problem we have is that cars and airplanes move more people around the globe and much faster than was the case over 80 years ago. So new disease strains can spread rather rapidly and can reach even remote places.
Still, its not all doom and gloom. The best way to avoid dying or getting very sick from a disease is to avoid exposure in the first place. The biggest advantage we have are far better ways to isolate ourselves from sick people. For instance, we live in less dense housing. Accounts of the 1918 epidemic describe immigrant families living in crowded New York City tenements where lots of people breathed each other's air. Individual families just had to have one member come home with the disease and soon ten or twenty others were all exposed to it and likely other people walking up and down the same staircases were exposed as well. By contrast, today we have smaller families and on average a much lower number of people living in each dwellling and more square feet of living space per person.
If it was suspected that some deadly disease on the order of the 1918 flu epidemic was on the scene then the most rational response would be to quickly and calmly reorder society in ways that would reduce risks of exposure. With this in mind one of the strangest (at least to my American eyes) things I saw riding subways and trains in Japan were people wearing surgical masks. Either they were sick and didn't want to pass their illness on to others or they wanted to avoid breathing in particles of influenza and cold viruses coughed into the air by others. Such a practice is easy to adopt. The inconvenience would be fairly minor and it beats dying. Even if there was a shortage of surgical masks all matter of cloth can be adapted to that purpose.
A reduction of exposure between humans can be accomplished in many other ways. People who go shopping can go less often, buy more per trip, and not go during rush hours when the isles are crowded. Optional activities such as vacations, club meetings, movie outings, concert attendance, and the like can be cancelled. People who are able to work from home can stop going into the office. Another simple thing is to avoid touching surfaces in public places. If you do then wash your hands quickly (perhaps with a bottle of antiseptic fluid). Better yet, wear gloves and avoid touching surfaces in public places. Also, when out in public avoid touching your face with your hands unless you've recently washed your hands. Even the people who can not change their daily routine will be at less risk if all those who can change their daily routine do so to the extent that they can.
Okay, so lethal epidemics can still happen. But we have lots of things we can do to reduce our risks of getting seriously ill or killed in such an epidemic. With all this in mind lets look at a recent development that has health officials thinking some pretty worried thoughts.
12 March 2003 | GENEVA -- Since mid February, WHO has been actively working to confirm reports of outbreaks of a severe form of pneumonia in Viet Nam, Hong Kong Special Administrative Region (SAR), China, and Guangdong province in China.
In Viet Nam the outbreak began with a single initial case who was hospitalized for treatment of severe, acute respiratory syndrome of unknown origin. He felt unwell during his journey and fell ill shortly after arrival in Hanoi from Shanghai and Hong Kong SAR, China. Following his admission to the hospital, approximately 20 hospital staff became sick with similar symptoms.
The signs and symptoms of the disease in Hanoi include initial flu-like illness (rapid onset of high fever followed by muscle aches, headache and sore throat). These are the most common symptoms. Early laboratory findings may include thrombocytopenia (low platelet count) and leucopenia (low white blood cell count). In some, but not all cases, this is followed by bilateral pneumonia, in some cases progressing to acute respiratory distress requiring assisted breathing on a respirator. Some patients are recovering but some patients remain critically ill.
Today, the Department of Health Hong Kong SAR has reported on an outbreak of respiratory illness in one of its public hospitals. As of midnight 11 March, 50 health care workers had been screened and 23 of them were found to have febrile illness. They were admitted to the hospital for observation as a precautionary measure. In this group, eight have developed early chest x-ray signs of pneumonia. Their conditions are stable. Three other health care workers self-presented to hospitals with febrile illness and two of them have chest x-ray signs of pneumonia.
15 March 2003 | GENEVA -- During the past week, WHO has received reports of more than 150 new suspected cases of Severe Acute Respiratory Syndrome (SARS), an atypical pneumonia for which cause has not yet been determined. Reports to date have been received from Canada, China, Hong Kong Special Administrative Region of China, Indonesia, Philippines, Singapore, Thailand, and Viet Nam. Early today, an ill passenger and companions who travelled from New York, United States, and who landed in Frankfurt, Germany were removed from their flight and taken to hospital isolation.
Due to the spread of SARS to several countries in a short period of time, the World Health Organization today has issued emergency guidance for travellers and airlines.
“This syndrome, SARS, is now a worldwide health threat,” said Dr. Gro Harlem Brundtland, Director General of the World Health Organization. “The world needs to work together to find its cause, cure the sick, and stop its spread.”
There is presently no recommendation for people to restrict travel to any destination. However in response to enquiries from governments, airlines, physicians and travellers, WHO is now offering guidance for travellers, airline crew and airlines. The exact nature of the infection is still under investigation and this guidance is based on the early information available to WHO.
Countries are starting to discourage their citizens from travelling to areas where SARS has been reported. Thailand joins Singapore and Taiwan in urging their citizens not to go to Hanoi or southern China.
Passengers are being required to fill out health forms indicating whether they had been to the affected areas, and airlines have been instructed to report immediately if any passengers begin exhibiting symptoms.
The announcement follows similar moves by Singapore and Taiwan, which have both urged their citizens not to travel to Hanoi in Vietnam or southern China "unless absolutely necessary".
"It is either a new germ which hasn't caused a disease before or is a more common germ which has undergone a large change," David Bell, a public health physician at the Manila-based WHO Western Pacific office, said.
"If it is a new organism -- which has undergone significant change -- it may be more difficult to identify," warned Rob Condon, a WHO epidemiologist at the same office.
World Health Organization official David Heymann is clearly worried.
"It is not a very good situation," said Dr. David L. Heymann, a top expert in communicable diseases at the health agency. "It is a very difficult disease to figure out, and this has been going on for the last 10 days to two weeks."
Influenza has not been ruled out as the cause.
Among the survivors, "no one has gotten well yet," Dr. Heymann said in an interview. "It is not clear what is going on, and it is not clear what the extent of spread will be," particularly because "these are areas where there is a lot of international travel," he added.
Dick Thompson, a WHO spokesman in Geneva, could recall no such emergency travel advisory being issued in recent memory.
"Until we can get a grip on it, I don't see how it will slow down," said Thompson. "People are not responding to antibiotics and antivirals, it's a highly contagious disease and it's moving around by jet. It's bad."
Now that so many health authorities and medical doctors are attempting to identify victims of this disease it may be possible to contain it. One advantage we have today that didn't exist over 80 years ago is that information travels even more quickly than people do. A lot of the initial victims were hospital workers. One would expect the rate of infection of health care workers to drop as they recognize the disorder more quickly and take more drastic measures to avoid exposure from infected patients. However, one concern there is that in less developed countries the health care workers may lack the kinds of facilities and supplies needed to reduce their own degree of risk. Therefore the health care workers in less developed countries may end up either spreading the disease or they may turn away the sick and therefore the sick may not be properly isolated. Whether efforts at containment will work remains to be seen.
Will this disease spread and kill massive numbers of people? Don't know. Its certainly a story to watch very carefully.
Update: Encouraging news about SARS comes from a CDC press conference. Dr. Julie Gerberding of the CDC says the pattern of transmission so far has been through close personal contact.
QUESTION: And also, do we know how contagious? I mean if I was on a subway car with someone who was ill, could I get it from them, or do you need to have that close like I'm-taking-care-of-me kind of contact.
DR. GERBERDING: What we know so far from the investigations in progress are that it's very close personal contact of the type defined by WHO as having cared for, having lived with, or having had direct contact with respiratory secretions and body fluids of a person with the diagnosis. So there is no evidence to suggest that this can be spread through breath contact or through assemblages of large people; it really seems to require a fairly direct and sustained contact with a symptomatic individual.
If pattern of transmission continues then the chances of containing the disease will be much better. If it becomes as easy to transmit as a cold or regular influenza then containment would be much more difficult and perhaps impossible. So far there has been no indication whether the disease is transmissible during the asymptomatic incubation period. Whether it is will also affect the ability to slow or stop its spread.
Update II: Even if SARS doesn't turn out to be a massive killer plague (and its pattern of transmission suggests it will not be) we are still vulnerable to being killed off by a pathogen that hops into the human population from another species and that mutates into a virulent form. We have had close calls that have been contained such as the 1997 chicken influenza that was extremely deadly in humans.
In 1997 epidemiologists and public health officials from around the world got their first glimpse¹ of an entirely new variety of human influenza. Known as subtype H5N1 for the surface proteins which the virus carries, the new strain had only ever previously been observed in birds. Ominously, the effect of H5N1 on poultry had earned it the evocative title of "Chicken Ebola." And when it surfaced in the human population of Hong Kong last year it proved to be almost as deadly.
How deadly? Even with the advantages of intensive-care treatment, fully one third of the first 18 confirmed cases never recovered. They died.
What is needed is the ability to develop and produce vaccines more rapidly. DNA vaccines are held out by some researchers as promising faster and lower cost manufacture with fewer side effects than many conventional vaccines. However, another promising approach is to use bacterial viruses knows as bacteriophages to produce vaccines very rapidly and cheaply.
BALTIMORE – March 10, 2003 – Genetically altered bacterial viruses appear to be more effective than naked DNA in eliciting an immune response and could be a new strategy for a next generation of vaccines that are easy to produce and store, say researchers from Moredun Research Institute in the United Kingdom.
"In theory, millions of doses can be grown within a matter of days using simple equipment, media and procedures," says John March, one of lead researchers presenting findings at the American Society for Microbiology's Biodefense Research Meeting.
Bacteriophages are viruses that infect bacteria but not humans. In this particular study, March and his colleagues used a bacteriophage as a vehicle for genes from hepatitis B virus in mice and compared its ability to elicit a protective immune response with a vaccine made of naked DNA. They found that not only could the bacteriophage induce an immune response, the number of bacteriophage they needed was less than 1 percent of the number of pieces of naked DNA required to mount an effective immune response.
Using bacteriophages to deliver vaccine components offers several advantages over vaccination with naked DNA, says March. The DNA is protected inside the protein shell of the virus making it longer lasting and easier to store. In addition, bacteriophages have a large cloning capacity, making large-scale production cheap, easy and extremely rapid – important attributes considering the current bioterrorism threat when sudden demands may be placed on vaccine stocks.
In order to produce vaccines the vaccines first must be developed. One has to have a design for a vaccine. Therefore the other needed element of a fast response strategy for new strains of influenza and even for new kinds of pathogens is to have high isolation labs that are equipped to rapidly take apart a pathogen and to develop vaccines for it. See my recent post United States Lacks Sufficient Biodefense Lab Space. What is needed is not just ultra-secure and ultra-isolated lab space. The labs would need to be equipped with or be located near labs that capabilities to do DNA sequencing, protein sequencing, protein structure determination and other relevant capabilities. Properly designed and equipped such labs could work on longer term problems between crises but when a deadly naturally occurring or man-made pathogen threatened to cause massive numbers of fatalities the best microbiologists and virologists could staff them and work to develop vaccines and drugs.
Update III: The illness may be caused by a paramyxovirus.
There is a long list of other candidates, with a family of microbes called the paramyxoviruses "certainly ranking on the top of most people's thoughts," said Klaus Stohr, a WHO virologist and epidemiologist who is helping to direct the investigation.
Update V: To reiterate for those who are worried that SARS could become an enormous killer: It is spreading slowly. It appears to require fairly close contact to catch it. It does not appear to be as easily transmitted as many cold and influenza viruses. In a March 17, 2003 press conference Dr. Julie Gerberding, Director of the Centers for Disease Control and Prevention, says SARS is not being transmitted by casual contact. (bold emphases mine)
We know that the disease is so far limited to people who have had very close contact with cases. Most of the individuals are health care personnel who have been in direct contact with either the patient or body fluids from the patient. We also know that household contacts are at risk, particularly if they've had direct and sustained contact with sick individuals.
So far the cases are limited, as Secretary Thompson said, to individuals who have either lived in parts of Asia that are affected, or who have recently traveled from those areas.
We believe the incubation period is approximately 2 to 7 days, although as new information unfolds, that may be updated. So the travel advisories that have been issued stipulate that individuals returning from those areas with fever and respiratory symptoms within 7 days of their departure should seek medical attention to be sure that they are not in the early stages of this syndrome.
We also know that there is no evidence so far that persons not in direct contact with suspect cases are at risk. We have not identified any people with casual contact or indirect contact. I think we were reassured by the investigation here in Georgia, where there was an individual who acquired this infection presumably from family members, was here in this city while sick, was involved in activities that involved exposure to others in a workplace setting, and there is no evidence of spread from that kind of contact in the workplace.
Nevertheless, I stress again this is an ongoing investigation. We certainly don't have all the information we need to know to have certainty about any of these issues, and we will just simply have to update you as we go forward.
The most important thing that we need to do is to prevent spread of this infection, and I'll tell you some of the things we're doing about that right now. But the second most important thing is to figure out what's causing. This appears to be a contagious infectious disease, and as I said, limited to health care personnel and close household contacts. That suggests spread by the droplet route, and that's why our infection control precautions emphasize prevention of droplet spread through the use of face shields and gowns and gloves.
Update VI: The disease is increasingly looking like it is not spreading. Victims are popping up in more countries but the vast bulk of them all were infected in China or Vietnam. Therefore a general outbreak all around the world is looking less likely. Now that the knowledge about its symptoms has been widely disseminated victims are rapidly isolated and health care workers protected from exposure. Hopefully this trend will continue and the disease will be contained. The disease increasingly looks like a new pathogen
"As time goes by that is increasingly likely, simply because so many people have run so many tests," said Iain Simpson, a spokesman for the World Health Organisation (WHO).
"If it is something we already knew about we would almost certainly have identified it," he told Reuters.
While this disease looks like it is going to be successfully contained it should serve as a wake-up call that we are ill-equipped to deal with a deadly disease that spreads easily and that does break out into the general population. Some day a much more deadly influenza strain will cross over from fowl or swine into humans and as of yet we are unprepared to effectively deal with that eventuality.
Update VII: SARS now looks to be much more infectious than previously thought. See my later post Fears Grow That SARS May Spread Into Pandemic.