World races to identify mysterious pneumonia
| • | Deadly illness has some canceling trips to Asia |
| • | U.S. urged to take lead in detecting new diseases |
By Dan Vergano and Steve Sternberg
USA Today
Health officials said that the mystery pneumonia responsible for at least nine deaths worldwide is spreading, with 14 possible U.S. cases under investigation.
World Health Organization teams are working with health officials around the world, including investigators at the U.S. Centers for Disease Control and Prevention, to identify the still unknown virus or bacteria responsible for the disease, known as severe acute respiratory syndrome (SARS).
The disease has spread to 10 countries in the past three weeks. WHO officials have confirmed 167 cases and four deaths, two in Asia and two in Canada. China reports another 350 cases and five more deaths since the original November outbreak. The number of dead could rise to 11 if a French doctor who died at a hospital in Vietnam and a Chinese professor who died this month in Hong Kong are confirmed SARS cases.
Suspected new cases have cropped up in Britain, Germany and Cambodia. CDC officials downplayed the likelihood that all 14 suspected U.S. cases will turn out to be SARS, saying only four seemed more than remote possibilities.
This weekend, the CDC issued a travel advisory calling for the postponement of all nonessential travel to outbreak centers in Hong Kong, Hanoi and China's Guangdong Province until further notice.
The driving force behind WHO and CDC actions is the specter of the 1918 flu epidemic that killed at least 20 million people worldwide, says CDC head Julie Gerberding. The SARS outbreak is a "wake-up call," she said, with some characteristics of the worst-case scenario — a highly infectious disease spread globally by air travel — that health officials hope to avoid by issuing travel advisories.
"It's important because it's an unknown disease, it affects hospital workers and it has traveled widely," said David Heymann, head of infectious diseases at WHO. "Countries need to know about it so they can isolate cases so they don't have local outbreaks."
The new patients reported in Hong Kong, Singapore and elsewhere are family members or healthcare workers with close exposure to patients, not people with only casual contacts.
"Face-to-face" contact seems key, Gerberding says, suggesting that droplets or other body fluids from patients, who often are wracked by coughing, may be the primary transmission route.
Laboratory workers are racing to identify the culprit. They're attempting to culture the responsible germ, testing it against antibodies to other illnesses and using genetic testing. Some physicians suggest it may be a virus, because immune-system related white blood cell counts go down, a common event in viral diseases.
Gerberding says the CDC is looking at all possibilities, noting the agency has been hampered by earlier difficulties in getting samples of the disease.
Yesterday, specialists at the Institute for Medical Virology at Frankfurt University in Germany said samples from two people there resemble a paramyxovirus, the family of microbes that causes measles, mumps and canine distemper. There is no treatment for that virus group.
The finding is the first potential clue to emerge in the three weeks since the illness came to the attention of health experts.
Dr. Wolfgang Preiser, a consultant virologist at Frankfurt University Hospital, urged caution over his group's findings, which are based on results from an electron microscope. Other more rigorous work, such as genetic testing, has not been done.
"It could possibly, potentially be the agent responsible for SARS, but we don't know at this stage," Preiser said. "The size fits a paramyxovirus. The structure, as far as we can make out, fits."
Samples were being sent today to a specialist lab in Rotterdam, Netherlands, which has previously identified new paramyxoviruses.
Infectious disease experts express some optimism that the ailment seems unlikely to spread more widely.
"Early on, this one doesn't seem to be spreading like wildfire," said epidemiologist Marjorie Pollack of the International Society of Infectious Disease. A mystery disease often looks more deadly at first glance, Pollack said, because the most seriously ill patients are the ones first noticed by doctors.
Another source of optimism is a new Chinese report that says after infecting hundreds of people, the original outbreak has been curtailed, suggesting it may weaken over time.
Georgia Division of Public Health investigators report that airline passengers who traveled from Atlanta to Toronto with an infected Canadian patient showed no signs of illness, a finding that Gerberding called reassuring.
Health authorities are still striving to identify an effective treatment for SARS. A high percentage of patients who develop early symptoms go on to develop severe pneumonia, making it crucial they seek treatment early.
The Associated Press contributed to this report.
