Late last week, WHO and the U.S. Centers for Disease Control and Prevention sent epidemiologists, pathologists and infection-control specialists to Hanoi and Hong Kong. But for now, regional health-care professionals remain baffled by SARS. Dr. John Tam, a medical-virology expert at the Chinese University of Hong Kong, says, "There's no evidence of how this began or where it came from. We really have no idea what this is, no theories whatsoever." The outbreak may have started this winter when 305 people in Guangdong were infected with atypical pneumonia; five of them died. Then, early this month, an American businessman who'd traveled to Hanoi from Shanghai via Hong Kong was admitted to a Hanoi hospital with a similar affliction. His case sparked further concern when he was airlifted to Hong Kong and scores of health-care workers in Hong Kong and Hanoi, many of whom had treated him, came down with similar symptoms—typically, a high fever followed by a dry cough, muscle aches, headache, sore throat and severe breathing difficulties.
The working theory, says Dr. Tam, is that the illness is spread by airborne respiratory mucous and saliva droplets. In Hong Kong, where 47 patients were under observation for pneumonia by the end of last week, the Department of Health urged at-risk hospital workers to wear protective gloves, masks and gowns.
Singapore issued its advisory after three people who had recently been in Hong Kong and six others who'd been in close contact with them since their return were struck ill. The disease has continued to jump borders with terrifying rapidity: last Friday, medical officials in Toronto announced that a woman named Kwan Sui-chu had died in the city on March 5, shortly after returning from Hong Kong, and that five of her relatives—who had not been to Hong Kong recently—were also ill. One, Chi Kwai Tse, died on March 13.
Doctors see no connection between the atypical pneumonia and the avian flu that has plagued Hong Kong in recent years. Still, officials worry that the city could be stigmatized as an epidemiological hot zone. Last Friday, Hong Kong's Secretary for Health, Welfare and Food Yeoh Eng-kiong pleaded for calm. "Words like 'Hong Kong has been quarantined' are detrimental to Hong Kong," he said. But if the disease keeps spreading, figuring out the proper spin on an outbreak should be the least of anyone's concerns.