In the struggle to contain SARS, Ma Lin is the man with his finger in the dike. Ma is the vice director of the center for disease control and prevention (CDC) in Guangzhou, and it's his job to track every suspected SARS victim in the capital of China's Guangdong province. That makes him one of the busiest men in China. Last Thursday, a Guangzhou man reported by his employer as running a fever was refusing to submit to a SARS examination. The response was instant. "Tell him he can deal with us now, or deal with the police later," Ma says, dictating an order to one of hundreds of health officials working around the clock. He turns to a reporter from TIME. "The police haven't actually become involved, but people always respond to the threat."
The health department is not normally an agent in mainland China's feared security apparatus, but decisive measures like this seem to have enabled Guangdong, birthplace of SARS, to stabilize the spread of the disease. While Beijing panics, Shanghai quibbles and Hong Kong continues to flounder, Guangdong has apparently seen a reduction in new cases from a peak of almost 50 a day in February to an average of nine for the past month, although it has hit the teens in recent days. "If SARS can be contained in Guangdong," notes World Health Organization (WHO) Beijing representative Hank Bekedam, "it becomes clear that strong action can help other provinces."
So what's Guangdong's secret? First, according to WHO sources, provincial officials on Feb. 3 set up an effective system of reporting new cases and disseminating information among its health-care workers. Unlike in Beijing or Hong Kong, where SARS patients have been scattered throughout the network of hospitals, Guangdong has consolidated them in a handful of its best hospitals. On Feb. 11, when the province publicly admitted to 305 cases, it was already running a central command to coordinate the fight against SARS. "We're tracking down every suspected case, quarantining patients and letting them go only after we're sure they're not infected," says Huang Fei, director of the command office. In the absence of a vaccine or effective treatment, that kind of dogged, shoe-leather epidemiology is vital to bringing an outbreak under control.
A look at how suspected cases are handled reveals a level of sophistication probably unseen in other parts of China. On April 20, Li Junhua, a worker on a construction site, boarded a bus for the five-hour ride to his home province of Hunan. Near the border with Guangdong, the man sitting behind the bus driver suddenly died. The driver contacted the police, who 10 minutes later arrived with health officials. They distributed masks and ordered that nobody was to leave the bus as the officials performed a background check on the dead man. "We were terrified he had died of SARS," says Li. Nine hours later, the officials had their result: the dead man's name turned up on a hospital computer as having been treated days before for a stroke. Doctors concluded the case was not SARS, but still recorded contact details of everyone on the bus and forwarded the list to the CDC in Guangzhou, where Li's contact information remains on file. "The whole process was remarkably efficient," Li told TIME by telephone from his home in Hunan.
Perhaps even more crucial, Guangdong quickly recognized the importance of protecting its medical staff, which early on accounted for nearly 40% of all SARS cases. After an initial delay, in late February front-line workers received full-body protective suits for use in dangerous cases of the disease something doctors and nurses in Hong Kong are only now being given. In the past month, the number of new SARS cases among health-care workers has fallen steadily to "basically none," according to Huang. SARS wards in Guangdong are well ventilated, with open windows and fans circulating air, which doctors in the province and the WHO alike believe plays an important role in preventing hospital infections.
Politically, though, Guangdong has acted as shamefully as Beijing and those mistakes have cost the rest of the world. The province dithered in January when it first identified the virulent new atypical pneumonia that would later be labeled as SARS, losing a chance to stop the disease in its tracks. Even after Guangdong had set up its efficient response system, officials there failed to share their expertise with Beijing and Hong Kong, and misrepresented the extent of the deadly new disease. Although the WHO is "pretty satisfied" with the way the outbreak has been handled medically, "that's distinct from how it was handled politically," says Peter Cordingley, WHO's Asia spokesman.
But infection-control methods alone seem unlikely to account for the SARS tally gap between Guangdong and neighboring Hong Kong, the latter having recorded over 130 more cases in only a month-and-a-half, with a fatality rate that's significantly higher than Guangdong's reported figure of 3.5%. Dumb luck plays a part. Guangdong officials say the province hasn't suffered a single explosive outbreak along the lines of Amoy Gardens in Hong Kong, where 321 people were infected, possibly via contaminated sewage, in a matter of days. That sudden mass of seriously ill patients spread SARS through the local community and overwhelmed hospitals, directly leading to more infections among health-care workers.
It's also possible that Guangdong natives have built up herd immunity to SARS, which occurs when a significant percentage of a population has developed antibodies against a specific disease, slowing its spread. But Malaysian microbiologist Dr. Lam Kai Sit notes that "with SARS, the incidence is so low there cannot be much immunity in the general population." Herd immunity could be aided by large instances of asymptomatic infection (infections with no sign of disease), but scientists have no way of knowing if such cases exist without using wide-scale diagnostic tests.
A more likely, and frightening, possibility is that the unstable SARS coronavirus has mutated since it left Guangdong, perhaps into a more virulent and contagious form. Scientists at the Beijing Genomics Institute announced last week that there were significant genetic differences between coronavirus samples sequenced from patients in Guangdong and in Beijing. In Hong Kong, doctors believe the virus may have mutated when it infected Amoy Gardens residents, who suffer unusual symptoms (including severe diarrhea) and have a higher fatality rate. Says Dr. Michael Lai, a coronavirus expert at the University of Southern California: "As the virus responds to different environments, different strains will emerge."
That possibility weighs on the minds of Guangdong's health officials, who know the province is just one superspreader away from a new outbreak. If SARS returns, it could spread rapidly among the province's 31 million migrant workers, who live in cramped dorms and enjoy few health services. "Even just one case a day is a problem," says Chen Rongchang, vice director of the Guangzhou Institute of Respiratory Disease. "One person could easily pass SARS on to 10 people, and then to a hundred. The virus is not dying out." Fortunately, neither is Guangdong's will to stem the tide on this deadly disease.