'A Matter of Hygiene'.(controlling contagious diseases; severe acute respiratory syndrome)(Interview)

Each year, it seems, a new microbe emerges to strike fear in the hearts of microbiologists--and, every once in a while, the rest of us as well. SARS is only the most recent of a succession of new pathogens to have emerged in recent years. Health experts worry that our global culture means that many more, and more destructive, pathogens are on the way. NEWSWEEK's Anna Kuchment spoke with Robert Webster, professor of virology at St. Jude Children's Research Hospital in Memphis, Tennessee, about the threat. Excerpts:

As a virologist and influenza expert, what has occurred to you as you've watched this epidemic unfold?

I guess the key question in my mind is, is it going to become a pandemic? A pandemic is something that spreads throughout the entire world, and this seems to be heading in that direction. I have been watching this situation with great concern, because the worst pandemic that we know about is the 1918 flu pandemic, and the death rate in this thing right now [about 3.5 percent] is exceeding 1918. That's an alarming mortality rate.

A recent report from the U.S. National Academies, to which you contributed, warns of a coming "microbial perfect storm." What does that mean?

I think it's a perfect analogy. Just as with a meteorological storm, several factors have come together in this region of southern China, including high population density and a booming economy. You know, the Chinese are more wealthy now than at any time in their history. They eat much more meat and pigs and chickens and ducks, and that means many more animal-human contacts. This agent, I would bet, came from an animal source.

Why are scientists predicting more such epidemics?

If you go back over the past 10 or 20 years, you'll see there have been emerging infections all over the globe, almost every year. HIV is still the worst one that has appeared recently. Another scary one was the Nipah virus in Malaysia, which went from bats to pigs [to humans in 1996]. There was also the Hendra virus in Australia that went from bats to horses [to humans in 1994], and H5N1 [the 1997 flu outbreak in Hong Kong that came from birds]. As the population of the world goes up, we can expect more of these things to occur. We do things that make these things happen. We bring these things on ourselves, as it were. Not intentionally, but just by increasing our population density, by cutting down trees, traveling more in planes. These are the factors that bring these things to the fore.