Experts fear new SARS definition misses cases--Questions raised about containing spread of disease
Tom Blackwell <a href=www.nationalpost.com>National Post Wednesday, May 07, 2003
A revised case definition of SARS may be excluding many people who have the virus, raising questions about whether quarantines are catching all those who could potentially spread the disease, according to a paper published yesterday by Canadian scientists.
The research paper, published yesterday in the online version of the Journal of the American Medical Association (JAMA), marks the second recent suggestion by experts that the ailment lurks in a significant number of individuals who do not meet the classic profile of a SARS patient.
A Health Canada scientist said last week that lab tests had found the strain of coronavirus thought to trigger the illness in 14% of patients deemed not to have SARS.
The JAMA paper, written by researchers at several Toronto hospitals and the University of Toronto, looked at 144 cases of the city's outbreak.
It notes the current case definition used worldwide excludes "a significant number" of people who have fever and had possible contact with SARS but no respiratory symptoms, such as a dry cough or shortness of breath. Such people would not be considered probable or suspect cases.
"This has important public health implications," the authors wrote. "Such individuals may actually have acquired the virus that causes SARS without developing the full syndrome. Accordingly, they and their contacts may require quarantine."
The cases examined by the group were all classed as probable or suspect SARS cases based on an early definition from the U.S. Centers for Disease Control. But under the criteria now used by Health Canada, the CDC and the World Health Organization, 16 would not be considered SARS cases, the paper said.
Dr. Frank Plummer, head of Health Canada's national microbiology lab in Winnipeg, said last week there is concern the non-SARS patients who tested positive for the coronavirus may be able to infect others, but there is no evidence yet of that happening.
Meanwhile, the outbreak showed further signs of weakening in Ontario yesterday, as the number of probable cases under treatment dropped by two to 29.
But more than a dozen countries seem to have doubts about Canada's safety. A week after the WHO lifted its controversial advisory against non-essential travel to Toronto, several countries still have similar alerts in effect about the city, according to Foreign Affairs Department records. They include South Korea, Venezuela and small nations that do not produce many visitors to Canada: Cayman Islands, Kuwait, Lebanon, Luxembourg, Macedonia, Malta, Nepal and Singapore.
Another group of countries has advisories that suggest their citizens avoid visiting Canada altogether, the Foreign Affairs records indicate. They are: Bhutan, Cooke Islands, Jordan, Libya, Malaysia, Mongolia, Panama, Uruguay, Vietnam and Yemen.
Foreign Affairs continues to tell nations there is no reason to restrict travel to Toronto, Reynald Doiron, a department spokesman, said.
Tourism Toronto is also spreading the word, writing to all Canadian missions abroad and to foreign embassies in Canada to point out the current status of the outbreak, Bruce MacMillan, president of the tourism agency, said.
"We've been successful in many cases and not in others," he said.
A major drug company yesterday addressed another fall-out of the epidemic: skin irritations suffered by health care workers who have to repeatedly wash their hands and use harsh antiseptics.
Pfizer Canada donated 40,000 tubes of its Lubriderm skin lotion, with a retail value of $120,000, to several Toronto hospitals.