With the alert, health officials in several Asian countries (Philippines included), Canada, France, Germany, and the United States shifted to control mode as they scurried to identify and quarantine potential carriers-travelers from China, Vietnam, and Hong Kong who might have had contact with sick people during their travel. (No case has been confirmed in the Philippines as of press time. But officials say the high number of travelers coming to the Philippines from Hong Kong continues to put the country at risk.)

    The alert also sent scientists in 11 laboratories in 13 countries on a race to identify the cause of the mysterious respiratory disease and find the antidote.

    Twelve days after WHOI issued the alert-with 17 deaths and 456 cases reported-the disease appears to have been placed under control.

    "The outbreak we feel is on its way to containment, at least outside of Vietnam, and Hong Kong and China," David Heymann, executive director of the WHO's communicable diseases unit, said on March 19, following announcement by two of the 11 laboratories working overtime that they have identified a link with the paramyxoviridae family of viruses.

    No secondary transmission of the disease had occurred since the global alert was issued, with "isolated cases" outside the three Asian countries being contained, the WHO said. "However, cases were imported to Canada before the world was alerted, there was transmission in Canada, Heymann said.

    WHO global alert coordinator Mike Ryan said the relatively large number of suspected cases that were subsequently ruled out showed that the global precautions were effective. "Many of these reports that you will hear will turn out to be spurious. The indication is that the system is working," Ryan added.

    "If paramyxovirus is confirmed to be the cause, WHO will be in a much better position to recommend a treatment," the organization said, adding that ribavirin "may be responsible for some degree of clinical improvement" among critically ill victims in Hong Kong.

China Syndrome

    The illness, tagged by the WHO as Severe Acute Respiratory Syndrome (SARS), was suspected of originating in China's Guangdong province, where a pneumonia-like outbreak downed 305 people in early February, killing five of them.

    No direct link has been established between the two outbreaks but China has requested the WHO for a team of investigators to look into the Guangdong outbreak.

    "It is likely [the Hong Kong and Guangdong cases are linked]. The only way to confirm it is when you have the bug and ...you start testing and testing very clearly what you see in Hong Kong, what you see in Hanoi...and what you see in Guangdong," WHO's China representative Henk Bekedam said.

    SARS is spread from person to person, but apparently only through sustained close contact. Nearly all the cases have occurred among family members and health workers involved in the direct care of suspected cases, according to health experts.

OUTBREAK A SARS victim is rushed to Bach Mai hospital in Hanoi where 58 cases of the deadly pneumonia-like illness have been reported. The virus has claimed the lives of 17 people in Hong Kong (10), Canada (3), and Vietnam (4) as of March 24. A total of 456 cases were reported in two weeks, excluding the 305 cases (five deaths) first reported in southern China in early February suspected of being having links with the SARS outbreak.

    Bekedam said the outbreak in Hong Kong was believed to have been triggered by a sick doctor from southern China who infected six people while staying at the Metropole hotel. He said while tests had not been done, because China has not provided WHO a sample specimen for testing, clues were coming in.

     "It's more likely there's a link to Hong Kong," he said. "We still have many questions...but it's getting more clear what is happening. The link has become much stronger."

    Bekedam's March 21 comments for the first time drew a connection between the cases in Guangdong and those in Hong Kong, heightening suspicions that cases elsewhere in the world could have stemmed from China.

    Hong Kong health officials have indicated that the SARS outbreak was triggered by the doctor.

    "There was one hotel [in Hong Kong] in which seven cases were found with related symptoms. They could trace also that one person came from the mainland," Bekedam said.

    Hong Kong's director of health Margaret Chan said all seven hotel guests stayed on the ninth floor of the Metropole hotel between February 15 and 27, and that it was believed the infection was spread when the Chinese doctor sneezed or coughed in the area around the elevator.

    The doctor, 64, and a 78-year-old Canadian woman, later died. The other five infected hotel guests-three women from Singapore, an elderly Canadian tourist and a local man-have made a recovery.

    Two deaths in Beijing have also been reported, but Bekedam said China told the WHO there were no cases so far outside Guangdong. But he pointed out the central government officials are not receiving data from local governments, pointing to flaws in China's case reporting system, which does not give the ministry power to order local governments to report cases.

    WHO officials suggested China learn from Hong Kong. "By daily reporting numbers [in Hong Kong]...it has not led to a major panic and it has kept people abreast of what's happening," said Alan Schnur, head of WHO's Communicable Disease Control office in China.

    He and Bekedam declined to say whether cases could have been prevented had China moved faster on the Guangdong outbreak, which first occurred in November, but was not made public by officials until February.

Virus Identity

    On March 23, University of Hong Kong scientists said they had cultured the virus that causes SARS. The team isolated the virus from the lung tissue of a patient who developed SARS after contact with the Chinese doctor.

    Chief virologist at Hong Kong University, Malik Pieris, called the new virus "tricky" and stressed it was important to conduct more study before forming any conclusions.

    The WHO said that with the virus now isolated, scientists could focus on characterizing the agent, determining its relationship with known viruses, and establishing a definitive identity.

    The results of the team's research will be shared among 11 leading laboratories in a global network set up by the WHO.

    Klaus Stoehr, a WHO virologist coordinating the network, said the success achieved through mutual cooperation of scientists around the globe gave hope that SARS could be contained.

    Said Stoehr: "Scientists, who are by default academic competitors, are now working virtually shoulder to shoulder. In less than a week, they have produced results which, in other circumstances, would likely have taken months or more. This rapid advance is fuelling the hope that SARS can and will be contained." Reports from AFP