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.
|Share |||Randall Parker, 2003 April 24 04:09 AM Dangers Natural Bio|