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SARS one year later: Still a mystery


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SARS one year later: Still a mystery

No cure for virus that killed 44 here

Sudden disappearance also a puzzle

ELAINE CAREY

MEDICAL REPORTER

The mystery began a year ago today when 78-year-old Kwan Sui Chu, a Toronto homemaker, died quietly at home after returning from a visit to Hong Kong.

She was the first Canadian victim of severe acute respiratory syndrome (SARS), although her death was initially attributed to a heart attack. It took more than a week to determine the killer was, in fact, a strange and mysterious illness.

A year later ? after 8,098 people in 29 countries contracted the disease and 774 of them died, including 44 in the Toronto area ? much about SARS remains unknown.

There is no reliable test to confirm it in its early stages, no drugs that have been proven to treat it and no vaccine to prevent it.

While there are diagnostic tests that confirm SARS after about 10 days, there isn't one for the early stages when it's needed the most ? when a patient arrives at a hospital emergency or a doctor's office with a respiratory infection.

Dr. Donald Low, chief microbiologist at Mount Sinai Hospital, has an encyclopedic knowledge of the corona virus that hit with a vengeance, alarming the world, then died out as quickly as it had developed.

"If we had continued to see outbreaks, there's no question it would have been a gigantic task," Low says. "But there was really no SARS and there hasn't been since it was declared gone last July. Because of that, it has made life a lot easier."

While four new cases were confirmed in China in January of this year, Low says they are not the same powerful strain that was allowed to gather strength in China for three months last year. More closely related to the strain that originally infected animals, the new one hasn't spread.

And while some speculate it could still reappear in someone who had already had SARS, Low says that's extremely doubtful.

"We've given them a year now and we have no example of a transmission occurring from a person recovering from the disease. There are 8,000 people out there that got infected. If this was going to reappear, we would have seen it by now."

Even more elusive has been the development of a vaccine to prevent it. At this point, SARS only exists in laboratories.

If a vaccine is developed, there are no people on whom to test its effectiveness, although a human trial of one vaccine has just started in China on 30 volunteers to test its safety.

They might develop antibodies to the SARS corona virus, "but the question is `will those antibodies protect somebody against SARS?'" Low says. "We'll never know that for sure if they're not challenged."

The World Health Organization said in November that it expects at least one of the competing SARS vaccines ? one of them being developed at the British Columbia Centre for Disease Control ? will be available in one to two years if another epidemic breaks out, but not for four or five years if one doesn't.

Drugs to treat it are even more elusive.

When SARS broke out, everybody was so busy dealing with it, nobody had the time to do clinical trials to evaluate the effectiveness of the drugs being used.

"We had just never been in a situation where we were challenged like this before," Low says. "What happened is we just started throwing things at patients, hoping for the best cocktails. At the end of it all, we really weren't much better off than when we started."

The SARS corona virus initially jumped to humans from the weasel-like civet cat and other exotic animals sold in Chinese markets.

From there, most researchers now believe it was spread like smallpox ? by large droplets that require face-to-face interaction. But occasionally, it seemed to spread through the air without any contact.

"We saw examples where patients were able to transmit it to a large number of people with minimal contact," Low says. "You have to wonder, did airborne transmission occur in that situation? We'll never know for sure."

"But we do know that in the great majority of cases transmission by direct contact and large droplet which makes it less infectious and more containable."

Despite the question marks, scientists now know an incredible amount about this disease, Low says.

"It's been amazing the amount of information that has evolved ? amazing since the disease was only investigated from the beginning of March until the end of June and we haven't seen any disease since then."

It happened because of unprecedented co-operation among research scientists around the world who dropped their rivalries and came together to wrest control of the disease.

"This was a first opportunity where a new disease presented itself and by setting up networks and laboratories, information was shared and clinical specimens were shared," Low says.

But that co-operation has stalled. With less urgency, researchers have gone back to the own work, knowing they have to generate unique results to get funding.

"But at least the precedent is there and if something comes up again, it will be a nice model," he says.

There's no real estimate of how many researchers and how much money is still being thrown at SARS ? but it's significant.

"Wherever I go, I'm always amazed there's somebody doing SARS research," Low says. "There was money made available and people took the opportunity to take what they were doing and apply it to SARS."

Despite the worldwide panic, in hindsight, SARS was never an extremely communicable disease, he says.

"When China declared a war on SARS, within weeks they brought it to its knees," Low says. "China was seeing several hundred new cases a day. Within weeks, it trickled down to nothing. You could never do that with influenza or other infectious diseases that have been in man for centuries."

But it is still difficult to understand how it spread so quickly around the world, then stopped.

"It really just doesn't make sense," Low says. "That's part of so much of what we don't know about this."

"Some people have raised the question `did what we do have anything to do with this thing going away? Did we actually make any difference? Was this something that was going to burn out anyhow?' I don't know."

WHO shocked the world with its unprecedented global travel alert on March 15. But the international health community responded and shut down this potential pandemic threat within four months. On July 5, WHO declared SARS had been contained. That represents "a remarkable achievement for a truly extraordinary international public health effort," researchers at the United States Centres for Disease Control and Prevention said in a report last week.

While SARS may never return, there are hundreds of other viruses that could cause the same devastation.

"That's the critical lesson to be learned ? surveillance, openness, sharing of information," Low says.

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I remember a few dimwits who have never even been to Toronto on some of the other forums suggest that SARS was a huge risk to anyone who visits Toronto even though it killed only a few dozen people all year compared to the hundreds that get murdered, for example, in other major cities every year.

SARS had zero effect on the way I went about my life. The same can be said for everyone I know. The number of people affected by SARS was statistically insignificant. You'd have a better chance being murdered, being run over by a car, etc.

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