"The hospitals have been closed and people are dying." A brief but chilling dispatch from the city of Guangzhou provided one of the outside world's first hints of the chaos in southern China's Guangdong Province as the mysterious disease now known as SARS spread unchecked. "When I got [the message], the province was already in disarray, with wholesale demonstrations in the streets," says retired U.S. Navy infectious disease investigator Stephen Cunnion, of his friend's report that he posted to ProMED-mail, an international infectious disease listserv.

Chinese officials have issued an extraordinary apology, effectively admitting that months of secrecy and denial after the new illness appeared last November created a case study in how not to handle an infectious disease outbreak. But in the end, China might have done the world a favor of sorts by providing a test of global readiness for an even more devastating future epidemic, whether naturally occurring or unleashed in an act of terrorism. With SARS (severe acute respiratory syndrome) having hit 22 countries by mid-April, world preparedness looks decidedly mixed.

"This was not the big one," says David Heymann, executive director for communicable diseases for the World Health Organization. His global alerts helped most countries to gird for SARS. But Heymann, whose group keeps a lookout for killer influenza strains that might emerge from the same region, admits that he is worried."We've always had confidence in Hong Kong," with its more modern and better-financed facilities, Heymann states, "whereas we didn't have confidence that China was prepared. Now I think we'll have to reassess Hong Kong."

The spread of SARS may have been no surprise to the Institute of Medicine (IOM), which in March quietly released a report, "Microbial Threats to Health: Emergence, Detection, and Response," an update to its startling 1992 analysis of gaping holes in U.S. defenses against a natural microbial assault. The IOM's latest analysis takes a global view and adds the risk of bioterrorism. Although the new study finds a few areas of improvement, it concludes that "the outlook is bleak on a number of fronts."

The report notes that global surveillance has improved--certainly none of the electronic systems that alerted the world to SARS existed in 1992--but experts judge it inadequate. Stephen Morse of Columbia University, an author of the original IOM report, believes that health surveillance is not comprehensive enough. "There's still a lot of frag- mentation of knowledge. Nature isn't standing still; neither are potential terrorists." For instance, even with its knowledge of the severe pneumonia outbreak in Guangdong as early as February 9, WHO could do nothing without Chinese cooperation. "What we never have is the teeth to go in if a country refuses information," Heymann laments. A full month passed until WHO learned about pneumonia patients who had infected an unusually high number of hospital staff in Hanoi, Hong Kong and Singapore. By then it was too late for Hong Kong, where authorities were caught off guard by the ability of SARS to spread not only through close contact but also through contaminated surfaces and possibly sewage. With dozens of new cases daily--many of them hospital workers--city health officials admitted defeat in containment efforts by early April.

Preventing such a meltdown in medical infrastructure is the rationale behind the current U.S. program to vaccinate health workers against smallpox. But there are no vaccines against some of the other "Category A" bioagents, considered the most dangerous potential weapons, such as the plague, tularemia and Ebola pathogens. And no vaccine or drug is effective against the suspected SARS agent, a coronavirus so different from others in that diverse viral family, it earned its own group designation.

SARS is unlikely to have been a product of bioengineering. Terrorists today are more apt to use known pathogens than to invent one, Morse says, but "a few years down the road, those who are technically sophisticated will be able to do things that are more imaginative."

The U.S. research enterprise must become equally imaginative, the IOM report warns. Because the threat of bioterrorism is part of a continuum with naturally occurring disease, the authors urge a national "comprehensive infectious disease research agenda." As if to make their point, a virus-gene microarray originally conceived for infectious disease research provided the Centers for Disease Control and Prevention's first clue that a coronavirus could be the SARS culprit. (Animal studies, too, have now implicated the coronavirus.)

Armed with a recently sextupled biodefense budget, the National Institute of Allergy and Infectious Disease (NIAID) is aggressively recruiting researchers to develop novel antimicrobials and vaccines. The proposed Project BioShield, targeted to Category A pathogens, would entice biotechnology firms with a $6-billion pool and a guaranteed customer in the form of the federal government. NIAID is also inviting biotech companies to work on a SARS vaccine, for which the potential worldwide market is probably incentive enough. Like the international laboratory network that identified the SARS agent with unprecedented speed and cooperation, the endeavor could demonstrate what modern science can accomplish when seriously applied to combating microbial threats.

Heymann hopes the world does take a lesson from the SARS experience: "It's excellent practice for what might be coming. When you think of other diseases that have spread, like AIDS, it's going to be very important that when the next one comes, we do it even better--much better."

Christine Soares is based in New York City.