Posted on 06/20/2003 8:26:27 AM PDT by Brian S
At a time when the SARS outbreak appears to be winding down, both in Canada and internationally, a number of puzzling and worrisome scientific developments cast a pall over the hopefulness.
These include:
Revelations that as many as 170 people in Canada may have had SARS without knowing it; Renewed worries that the SARS virus may be mutating; A warning that SARS may return with a vengeance in the fall, when respiratory diseases flourish; New research that suggests people with SARS may be slipping through the cracks because guidelines for diagnosing new cases are inadequate. The research, published in Friday's edition of the British Medical Journal, found that only one in four patients with severe acute respiratory syndrome at a Hong Kong hospital had telltale symptoms at the beginning of their illness, when they were most infectious.
Timothy Rainer, a physician in the accident and emergency medicine unit of Prince of Wales Hospital, said accepted diagnostic guidelines focus too heavily on respiratory-tract symptoms such as cough and difficulty breathing.
His research found the early stages of the disease are characterized by fever, chills, loss of appetite, vomiting, diarrhea and neck pain.
Canadian health officials said yesterday they are reviewing the findings and will try to be more careful. "We're looking at all the literature coming out of areas with SARS and will look at reviewing the case definition," said Brian Schwartz, co-chairman of the Ontario SARS scientific committee.
Officials also conceded yesterday that a number of SARS cases may have slipped through the cracks, but insisted this did not affect the severity or duration of the stubborn Ontario outbreak.
Tests conducted at the National Microbiology Laboratory in Winnipeg identified as many as 170 additional people, 120 of those in Ontario, whose blood tested positive for the coronavirus that causes SARS, even though they were not believed to have the disease.
Ontario officials yesterday played down the findings, saying there is no indication that these people spread SARS or that they actually fell ill. "They do not represent a new outbreak or a new cluster of SARS cases," James Young, Ontario's public safety commissioner, said at a press conference.
"These people are not a new group, and there is good evidence that they did not spread the disease in any way." Dr. Young said that the tests could be false positives because of imperfections of the new test, or that this group could have been asymptomatic: exposed to the disease, but showing no signs of illness.
At a SARS conference yesterday in Singapore, a number of scientists warned that the virus appears to be mutating. That means that, despite a sharp drop in SARS infections worldwide, it could resurface in an even more deadly and contagious form.
In fact, at a separate SARS conference in Kuala Lumpur, officials from the World Health Organization warned that SARS may simply be lying dormant — as many respiratory illnesses do during the hot summer months — and could return in the fall and winter. (This is the pattern of influenza and common colds, of which there are new mutations every year.)
Marie-Paule Kieny, head of the WHO's vaccine research program, said this possibility means that governments should invest heavily in finding a vaccine to prevent the virus from striking again in a mutated form.
She also warned that public-health officials cannot let their guard down because, as the virus mutates, it will become increasingly difficult to detect, raising the possibility of new outbreaks.
As of yesterday, the cumulative total of SARS cases was 8,462 worldwide, of which 804 were fatal.
There have been 35 SARS deaths in Canada, all in Ontario. Thirty-one people are being actively treated for SARS in the province. With a report from Associated Press.
Could be a 'rough' winter.
I would be concerned too. Be careful.
Revelations that as many as 170 people in Canada may have had SARS without knowing it...
can be viewed in a positive light. Which is, if you can be exposed to it, and don't suffer symptoms, then some percentage of the population has a natural immunity.
BTW, if they're here for the weekend they're going to have fantastic weather. High 70's and sunny the whole time.
I wonder how they came up with this number.
Yup. Could be a very positive sign. Maybe it is mutating to a less virulent strain.
One of the threads explained it. They did PCR tests on a lot of people and 170 showed to have developed antigens to SARS, without exhibiting symptoms. (...or something close to that.)
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