International health experts are expanding efforts to contain the spread of a mysterious pneumonia that has killed at least nine people. Hong Kong officials say the disease continues to strike health workers.
International officials fear the mysterious illness could be spreading across borders, as victims travel by air around the world. A doctor with an acute respiratory illness was taken off a flight from New York to Singapore on Saturday. The other passengers were temporarily quarantined when the plane stopped over in Germany.
The World Health Organization has released emergency guidelines to airline workers, warning them to look out for passengers with flu-like symptoms or difficulty breathing. The WHO refers to the illness as "Severe Acute Respiratory Syndrome" and warns that it is "atypical," because it is difficult to treat.
While no cases of the illness have been identified in the United States, the U.S. Centers for Disease Control and Prevention activated its emergency operations center. CDC officials are arriving in Asia to help trace the origin of the illness.
Most of the suspected cases of the disease have been found in southern China, Hong Kong and Vietnam. Singapore, the Philippines, Taiwan and Indonesia also report suspected cases. Most of the victims have been health-care workers.
In Hong Kong, at least 49 hospital workers have shown flu-like symptoms. On Sunday, Hong Kong officials said 42 of them appeared to have atypical pneumonia.
Yeoh Eng-kiong heads Hong Kong's department of health. He said that there is no noticeable increase overall in the number of atypical respiratory illnesses reported in the city. "It seems to have a predilection to affect health-care workers and very close relatives. We're interested in a very specific subset of atypical pneumonia," Ms. Yeoh said.
A Vietnamese nurse died of atypical pneumonia in Hanoi on Sunday. She and at least 30 co-workers became ill after caring for an American who died last week. A woman and her son died in Canada on Saturday. The mother apparently contracted the disease on a visit to Hong Kong. Last month, at least five people died in a pneumonia outbreak affecting at least 300 people in mainland China.
Scientists, however, say they cannot be certain the cases are all linked. Researchers have yet to pinpoint the cause of the disease.
Hong Kong hospitals have reported limited success in treating some patients with anti-viral drugs leading doctors to believe the illness is caused by a virus and not bacteria.
Historically, southern China has been a breeding ground for new strains of influenza, apparently as viruses have mutated and spread from poultry to humans in the region.