THURSDAY, April 17, 2003 (HealthDayNews) -- The number of U.S. residents who actually have been stricken by the deadly respiratory illness sweeping the globe may be far less than the total number of suspected cases reported in the country, federal health officials said Thursday.
Only 35 of 208 suspected cases in 34 states are now classified as "probable" cases of severe acute respiratory syndrome (SARS), Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention, told a news conference.
Those 35 people, or 17 percent of the total, have an illness that is consistent with the World Health Organization's case definition of probable SARS, a case definition the CDC is now adopting.
To be classified as a probable SARS case, a person must have pneumonia or acute respiratory distress syndrome. The other 173 suspected U.S. cases involved only fever or milder respiratory symptoms, Gerberding said.
"Probable cases are more likely to have the condition," she added.
Officials are not saying where the probable cases are; California leads the states with a total of 42 suspected cases, followed by New York, which has 22.
Gerberding cautioned that the relatively good news about the lowered U.S. case count is no reason "to let our guard down." There is much that is still not known about the disease, she said, adding "we are watching with great concern ... events in other parts of the world."
The U.S. revision stands in stark contrast to Southeast Asia, where the disease, now known to be caused by a new coronavirus, continues to surge.
Singapore reported another two deaths and Hong Kong reported four more deaths and 29 news cases on Thursday. That brings the total number of probable SARS cases worldwide to 3,389, with 165 fatalities, according to the official WHO tally.
However, many of those afflicted appear to have recovered, according to the WHO, which is now adding those numbers to its daily count. As of Thursday, 1,597 of the 3,389 cases are classified as recovered.
That does not yet include any numbers from the United States. And those statistics are not expected to be available anytime in the immediate future, according to CDC press officer Rhonda Smith. "We're still working to define what SARS is," which makes it difficult to define someone as recovered, she said.
In all, 25 countries have reported SARS cases. Hardest hit are Hong Kong, which has 1,297 cases and 65 deaths, and mainland China, the source of the epidemic, which now says it has 1,457 cases and 65 deaths.
The accuracy of China's numbers, however, have been challenged by world health officials who accuse the country of under-reporting SARS cases in Beijing, an accusation that officials there deny.
Asian officials have stepped up preventive measures, with Hong Kong announcing plans to take the temperature of outbound passengers at Chek Lap Kok airport. Those with a fever greater than 100.4 -- a first symptom of the illness -- will be referred to medical care.
In addition to high fever, other symptoms of SARS include chills, headache, malaise and body aches, a dry cough and difficulty breathing. Up to 20 percent of those affected need mechanical ventilation to breathe.
Some airlines, including Cathay Pacific and Singapore Airlines, have begun to pass out facial masks to passengers flying in the heavily afflicted areas. Cruise lines with itineraries in the affected areas are questioning passengers before they board, and some are requiring them to sign a form verifying they are not experiencing SARS-like symptoms.
In the wake of reports that some Asians -- and their restaurants -- have been shunned by Americans, Gerberding noted that an "epidemic of fear" often follows a disease epidemic. She urged Americans to have empathy for those affected here by SARS.
The initial suspicion that the new virus is spread by close person-to-person contact seems to be borne out by what is known about the 35 probable U.S. cases. Of those 35 people, 33 had traveled to mainland China, Hong Kong, Singapore or Hanoi, according to the CDC. One was a health-care worker who cared for a SARS patient and the other was a household contact of a SARS patient.
Earlier this week, a Netherlands research team succeeded in producing an animal model of the disease, infecting monkeys with the coronavirus suspected to cause SARS and then observing SARS symptoms. Scientists have also shown evidence of the new coronavirus in lung tissue recovered from a SARS patient, Gerberding said.
These two advances, in addition to the genetic sequencing of the virus, which both the CDC and Canadian researchers completed earlier this week, were crucial in determining whether the new coronavirus caused the illness.
More information
For more information on SARS, visit the World Health Organization or the U.S. Centers for Disease Control and Prevention.
