April 26, 2003
SARS Looks Set To Spread To Less Developed Countries

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.

Canada has also been too slow to do quarantines and to adopt extreme measures to protect health care workers.

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.

The long incubation period helps SARS to spread around the world.

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.

The US CDC reports that there is a preliminary study done in Hong Kong that shows SARS can survive on an exposed surface for at least 24 hours.

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.

Update III: Two more cases of SARS reported in Calcutta and Bombay.

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.

Share |      Randall Parker, 2003 April 26 03:41 PM  Dangers Natural Bio


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