MONDAY, March 24, 2003 (HealthDayNews) -- American health officials now say the overwhelming majority of 39 suspected U.S. cases of SARS involve people who traveled recently to Asia, where the deadly respiratory illness has hit the hardest.
The U.S. count of possible victims of the severe acute respiratory syndrome increased by 17 Monday, which moves the country to fourth place on the list of 15 nations reporting cases. New victim counts Monday from some of those countries, coupled with the revised U.S. totals, now bring the global total of SARS victims to more than 750 stricken and 22 dead.
Thirty-two of the people being monitored in 18 U.S. states had traveled recently to Asia, according to Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention.
The other seven, she told a news conference Monday, are "people who either have lived in the home with the case patient and had very close face-to-face contact or health-care personnel who had very close contact without using respiratory precautions."
Researchers now have a possible new virus as the cause of the mysterious illness. Gerberding said that the candidate is a previously unknown member of the coronavirus family.
Two coronaviruses are known to infect humans. One is responsible for about one-third of cases of the common cold, while the other frequently causes health-care-associated upper respiratory infections in premature infants.
The case for a coronavirus appears to be stronger than that for a paramyxovirus, which was the leading -- and only -- contender as the cause last week.
"There's evidence [for a coronavirus] in a variety of forms," Gerberding said. "We can culture it. We can see it on an electron microscope in respiratory fluids, we have specific assays that are picking it up in a variety of tissues and specimens."
The evidence also shows that one patient who had tested negative to coronavirus antibodies at the beginning of the illness developed antibodies and tested positive by the end of the illness.
"This could still be an incidental finding, but that's looking increasingly doubtful," Gerberding said. "The challenge is, we have a pretty nonspecific illness and we are dealing with families of viruses that are ubiquitous."
"Finding them in tissue is not the same thing as saying they cause the disease," she added. "But we have been able to localize them using pretty sophisticated probes and tissue techniques, and our confidence is building."
Currently, three groups of coronaviruses are known. The new virus, if confirmed, would probably fall into a fourth group. If confirmed, it's possible that the coronavirus is only one of two or more agents involved.
There are no treatments for illnesses caused by coronaviruses, but Gerberding said the U.S. Department of Defense was examining its existing arsenal of antivirals to see whether one would be effective against this particular bug.
Hong Kong, meanwhile, announced two more deaths and another 38 people infected with SARS, the Associated Press reports.
Among them may well be Hong Kong's chief health hospital official, who was hospitalized with pneumonia symptoms Sunday night. Health officials said he had been going through hospitals lately to offer moral support to medical workers and patients, the AP reports.
In Singapore, meanwhile, there were reports of 14 new cases as the government ordered 740 people who may have been exposed to SARS to stay home for 10 days, the AP said.
Health Minister Lim Hng Kiang said he was invoking the Infectious Diseases Act for what could be the first time since Singapore became an independent state in 1965, the AP said.
The deadly effect of the illness was also documented in Toronto, which reported its third death on Sunday. The victim, a man in his 70s who died Friday, contracted the illness after being placed in an observation room with a SARS victim who later died, the Canadian Press reports. The other victim was the son of a Toronto woman who died March 5 after apparently bringing back the infection from Hong Kong.
In addition, Canadian health officials are monitoring another cluster of about 12 people who appear to be showing symptoms of SARS, according to the Canadian Press.
Hong Kong's toll of infected people is now 260; Singapore now has 65, Vietnam has 58, and Canada has 11. The official World Health Organization count stands at 456 infected and 17 dead. However, that does not include two cases on the new U.S. list, and also does not include more than 300 illnesses and five deaths reported out of mainland China's Guangdong province.
The SARS spread is believed to have started in Hong Kong's Metropole Hotel on Feb. 21, when six strangers waiting for a ninth-floor elevator came in contact with a seventh person, a sick Chinese professor from Guangdong province who died in Hong Kong March 4.
The sequence of infections from that elevator wait have now been documented in Hong Kong, Canada, and Vietnam. In Hong Kong, it spread among many hospital workers and family members of initial SARS patients. In Canada, the Toronto woman who died passed on the infection to five of her relatives in Hong Kong and Toronto; two of them, her sons, are now also dead. In Vietnam, an American businessman infected hospital workers in Hanoi. The businessman died in Hong Kong, and a doctor and nurse died in Hanoi, which now has 63 cases.
The daisy-chain reaction can be seen in microcosm in Singapore, where at least 44 of its cases were passed on by three young women who were also at that hotel elevator.
This is how that particular sequence went, according to a New York Times report:
The three women transmitted the disease agent to nine health-care workers, nine family members, and three friends. Those 21 individuals, in turn, spread the illness to six health-care workers, four family members, and three friends. Those 13 then spread it to seven others: six health care workers and a family member.
Meanwhile, the CDC is keeping up its effort to locate possible cases. The agency has now issued about 52,000 alert cards to incoming passengers on planes and ships since March 15, said Dr. Marty Cetron of the National Center for Infectious Diseases in Atlanta.
Until a cause (and possibly a drug) is found, officials are recommending the same precautions as before. Patients are to be kept in respiratory isolation rooms while health-care personnel are being advised to wear respiratory masks as well as face shields, gowns, and gloves when appropriate.
"There's no specific treatment for this," Gerberding said. "The majority will be able to survive if they have good medical care, and we think that will be the case for most people."
More information
The CDC and the World Health Organization have updates and information on SARS.
