about Epidemiology & the department

Epidemiology academic information

Epidemiology faculty

Epidemilogy resources

sites of interest to Epidemiology professionals

Last Updated

10 May 2003

Source: Newsday, May 10, 2003

The SARS Mystery

Beijing: Source of majority of cases unknown


Beijing - Health officials here publicly acknowledged Friday that they do not know how the majority of SARS infections in the Chinese capital are occurring, and one of the World Health Organization's top officials said it "is impossible to say" whether the Beijing epidemic has peaked.

For several days Beijing's leaders have insisted that the epidemic appears to have peaked. Wednesday and Thursday, new case reports numbered 94 and 97, in line with the roughly 100 daily new cases of the past two weeks. Friday the numbers of newly confirmed cases fell to 48 and two deaths. Nationally China reported 118 new cases Friday and six deaths.

What frustrates health officials here is that most new cases are not associated with hospitals, which means people in this city are acquiring their infections somewhere else. But where?

In the earlier stages of the Beijing epidemic about a third of infections involved health care workers, and ailing doctors and nurses fill city hospital wards. But Beijing has worked to improve infection-control standards inside hospitals, quarantine severe acute respiratory syndrome patients and provide doctors and nurses with protective gear. The efforts are paying off, Beijing government spokesman Cai Fuchao said, because on Wednesday and Thursday only four of each day's new SARS cases were health care workers.

"Apart from hospitals there are other sources of infection in society," the city's top epidemiologist, Dr. Liang Wannian, said. "... Forty percent of new cases are in our control, under medical observation or in quarantine. For the rest of the cases we do not know who they are, or how they got infected."

It is possible Beijing is rife with situations akin to the now notorious Amoy Gardens outbreak in Hong Kong, in which more than 300 residents of a single apartment complex came down with SARS. The 60 percent unsolved cases currently are considered "sporadic," as if they spontaneously caught SARS. But in Singapore, Hong Kong, Vietnam and China's Guangdong province, the epidemics were characterized by clusters of connected cases, usually beginning with one highly infectious individual. So far, Beijing has not identified any clusters outside of the hospitals.

The government's inability to say where most of Beijing's SARS cases are coming from is frustrating WHO officials here. Dr. Henk Bekedam, head of the WHO team, on Thursday told Beijing's mayor, "We are not at all satisfied with the current analysis. You need to focus on these sporadic cases. You have to find out how they are getting the diseases. You might have an Amoy Gardens here and you can't do anything unless you figure out what is going on with your sporadic cases," Bekedam recalled in an interview Friday.

WHO Director General nominee Dr. Jong-Wook Lee flew into Beijing on Friday, met with Minister of Health Wu Yi and the minister of foreign affairs, and then flew to Geneva. In two weeks Lee, a South Korean, faces a perfunctory confirmation vote from the World Health Assembly, and he will become director general in July. After meeting with Wu, Lee spoke briefly with a handful of journalists.

Lee described the talks as "very frank," but noted serious shortcomings in China's understanding of its still-evolving epidemic.

"Right now the only way to deal with this problem is to find the source of the infections," he said, adding "reliable information is very important for that."

"We don't know yet" if Beijing is past the worst of its SARS epidemic, Lee said. " ... Everybody is now trying to analyze the data and make sense of it."

Without affirmation from WHO that China is on the right track, China's economy will continue to reel. As of Friday 109 countries had imposed travel restrictions on China, and Beijing was isolated by roadblocks.