New Clues on Killer Pneumonia Outbreak

Mysterious Illness Called SARS Continues to Spread, Potential Virus Identified

March 19, 2003 -- The number of people sickened by a mysterious deadly pneumonia called SARS continues to grow as researchers zero in on a potential cause.

The World Health Organization now estimates that 264 people have been diagnosed with SARS (severe acute respiratory syndrome), including nine deaths. Although no cases have been confirmed in the U.S., the CDC announced today that they are investigating 11 possible cases in people who recently returned from travel in the affected areas of Southeast Asia.

"The 11 cases we are reporting today have the travel history, fever, and respiratory symptoms that fall into the definition of a suspect case," says CDC Director Julie Gerberding, MD, in a briefing today. "We may find a completely unrelated cause for their illness, but for now they are on the suspect list."

WHO officials say SARS continues to spread to new countries, and cases have been reported in Canada, China, Taiwan, Germany, Hong Kong, Singapore, Slovenia, Thailand, Vietnam, and the United Kingdom. The vast majority of the cases of the pneumonia are concentrated in Hong Kong, Hanoi, Vietnam, and Singapore. All other reported cases have been linked to travel within the past 10 days to one of these affected areas.

Investigators also announced a potential break in efforts to identify a cause of the deadly pneumonia. Three separate laboratories in Germany and Hong Kong identified a strain of microbes that resemble the paramyxovirus, a family viruses that causes measles, mumps, and canine distemper, in samples from nasal swabs of two SARS patients.

But experts stress that this finding is preliminary and based on only a small number of the more than 200 cases reported. In addition, even if the presence of this virus is confirmed, it is still not clear at this point whether the virus is the cause of SARS or just a coincidental finding.

"Seeing something in a nasal swab is not the same thing as finding a causal relationship," says Gerberding. "A great deal more work needs to be done to determine if it is the cause of the infection."

Gerberding says it's not uncommon to find various forms of the paramyxovirus in nasal secretions during flu season, but it is promising that this type of virus was found in more than one location by more than one laboratory at this stage of the SARS investigation.

In addition, public health officials in Hong Kong announced today that seven of the initial SARS patients had been residents on the same floor of a Hong Kong hotel in February. At least two of those people were known to have had close contact with each other and this contact may have been one of the initial modes of transmission of the disease.

Officials have closed off the affected section of the hotel and are continuing their investigation to trace the source of the outbreak.

Experts say the illness seems to be spread only through direct, face-to-face contact, and there is no evidence to suggest that the disease may be spread through casual contact. The symptoms of SARS appear to develop within two to seven days of exposure.

The WHO broadly defines a case of SARS as someone with:

• A fever of greater than 100.4 degrees;
• One or more of the following respiratory symptoms: cough, shortness of breath or difficulty breathing;
• And either close contact with a known SARS case or a history of travel to one of the affected areas within the last 10 days before the emergence of symptoms.

Since the exact cause of the SARS has not been identified, the CDC recommends that doctors treat the condition as they would any other unexplained pneumonia case, including treatment with antibiotics.

The WHO says most of the cases have occurred in people who have had very close contact with other known cases, and more than 90% of those who have become ill with the condition are health care workers.

A CDC health alert advises travelers to Southeast Asia to contact their doctor immediately if they become ill with a fever and respiratory symptoms, such as cough or difficulty breathing, within seven days of travel to affected areas. A related travel advisory also states that U.S. citizens planning nonessential travel to the regions affected by the outbreak may wish to postpone their trips until further notice.

Officials say at this time there is no evidence to suggest that this mysterious pneumonia might have unnatural causes or is an example of bioterrorism. The pattern of disease outbreak is what would normally be expected from a contagious respiratory or flu-like illness, but the CDC says they are keeping an open mind about the issue.