March 21, 2003 -- The number of suspected cases of the mysterious pneumonia illness called SARS (severe acute respiratory syndrome) in the U.S. has now grown to 22 across 12 states, and for the first time CDC officials say they believe the condition may have been spread in this country.
Worldwide, suspected SARS cases have increased to more than 350 in 14 countries, but World Health Organization (WHO) officials say they're "cautiously optimistic" about identifying the cause of the mystery pneumonia and may soon be able to develop a test to screen for it.
In a briefing today, CDC Director Julie Gerberding, MD, acknowledged that at least two suspected SARS cases in the U.S. appear be the result of persons who developed the illness after travel to the affected areas of Southeast Asia and then infected a healthcare worker in one case and a close family member in the other.
Suspected SARS cases have now been reported in California, Hawaii, Maine, Massachusetts, New Jersey, New Mexico, North Carolina, New York, Rhode Island, Utah, Virginia, and Wisconsin.
Gerberding also said that two Americans included in the 22 suspected U.S. cases recently stayed on the same floor of the Hong Kong hotel that has been implicated as a potential source of the original infections. Earlier this week, officials said seven of the original SARS cases resided on the ninth floor of a Kowloon hotel in February and are thought to be among the original transmitters of the disease. Hong Kong health officials have since closed the affected section of the hotel.
Gerberding says that by tracing so many cases of severe acute respiratory syndrome back to the hotel, the outbreak is consistent with other naturally occurring infectious diseases by having a single source or person who is a particularly good transmitter. But she says the CDC is keeping an open mind about the possibility of terrorism under the current global climate, and authorities "are making sure not to leave any stone unturned in identifying the ultimate cause of the problem."
In another briefing in Geneva, WHO officials said at least two more laboratories have confirmed initial findings of a virus that might be the cause of the current SARS outbreak.
"We are now closer to reality that this Paramyxoviridae virus has caused this," says David Heymann, MD, executive director of the communicable diseases section of the WHO. But he says this represents a whole range of different viruses, from some that cause measles and mumps to others that cause common respiratory infections and sometimes may not even cause symptoms.
"Just because we found it circulating in some people does not mean that it is not circulating in others. A whole series of studies has to be done to find out if this is the cause," says Heymann.
WHO officials say it is promising that many of the known forms of the Paramyxoviridae viruses have already been excluded, which suggests that this might be a new form of the virus.
Despite the difficulties in identifying the exact cause of SARS, investigators today announced a major step toward developing a test that could screen suspected SARS cases. Officials say that a laboratory has now succeeded in growing an infectious agent in the laboratory that appears to cause severe acute respiratory syndrome.
When researchers added blood from patients recovering with SARS to a cell culture, the growth of the virus was halted, but blood from healthy people had no effect on the virus. That indicates that persons with SARS had developed antibodies to the virus, which provides strong evidence that the virus is the likely cause of illness.
"This is not just some light at the end of the tunnel," said WHO virologist Dr Klaus Stöhr, who is coordinating the collaborative laboratory efforts. "This is a real ray of sunshine."
Gerberding says the virus appears to be particularly dangerous and potentially deadly to even healthy individuals, and early isolation and early care is critical to managing the pneumonia and respiratory illness caused by SARS.
But Gerberding added that there is promising news coming out of Vietnam, where some of the first SARS cases were reported. In Hanoi, there are more reports of people recovering from severe acute respiratory syndrome and being released from the hospital.
"So in the absence of a cause, good supportive care can promote recovery," says Gerberding.
Until the cause of the mysterious pneumonia is identified, WHO broadly defines a case of severe acute respiratory syndrome 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, or an X-ray finding of pneumonia;
- 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.
Most of the SARS cases are concentrated in Hong Kong, Vietnam, and Singapore, but other suspected cases have been reported in southern China, Taiwan, Switzerland, Canada, Germany, Slovenia, Spain, Thailand, Ireland, Italy, and the United Kingdom.
Gerberding says severe acute respiratory syndrome appears to be transmitted only through close, personal contact with an affected individual, such as a family member or healthcare worker of an infected individual. There is no evidence to suggest that casual contact with someone with SARS can result in infection.
Symptoms of the mysterious pneumonia or the respiratory illness caused by SARS develop within two to seven days after exposure. A CDC health alert advises travelers to Southeast Asia to seek medical attention immediately if they become ill with a fever and respiratory symptoms, such as cough or difficulty breathing, within 10 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 SARS outbreak may wish to postpone their trips until further notice.
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