Disease forecasters prepare to predict next pandemic

By Judy Lin

Imagine that the AIDS epidemic with all its miseries and misunderstandings could have been prevented. Or that yet unknown microbes poised to ravage future generations could be discovered and stopped in their tracks.

Nathan Wolfe thinks it's possible.

"There's no reason to believe that pandemics will be harder to predict than earthquakes or tsunamis," said Wolfe, who is charting new territory in the nascent science of disease forecasting.

With the support of a $2.5-million Pioneer Award from the National Institutes of Health, the professor of epidemiology in the School of Public Health is creating a pilot system for exploring and understanding how viruses emerge.

Working at sites as farflung as Central Africa and Borneo, China and Malaysia, Wolfe and collaborators from UCLA and around the world are building a "viral museum," collecting and analyzing specimens of novel viruses in a critical step toward identifying ways to control potentially catastrophic pathogens. Wolfe's interest in disease forecasting stems from a decade of field work in the jungles of Cameroon, where he monitored the habits and the blood pathologies of bushmeat hunters and their kills. Last May, with colleagues Jared Diamond and Claire Panosian Dunavan, Wolfe published a paper in the journal Nature that concluded that major diseases throughout history have likely all found their way to humans via animals.

"Infectious diseases springing from wild primate populations regularly infect human populations of hunters and gatherers, a cycle that presumably has endured for millions of years," Wolfe said. Earlier, he and his colleagues were the first to demonstrate the ongoing transmission of retroviruses — the class of viruses which includes HIV — in the human population.

HIV, Wolfe noted, is effectively a bushmeat disease that made the jump from chimpanzee to humans generations ago but which until recently was primarily limited to a small number of cases. Globalization, however, has changed that.

"Previously, we lived in more or less isolated communities," Wolfe said. "Maybe disease would pop over from an animal to a community but only with the potential to either simmer through or flare through that population and then go extinct … Today, however, that population is effectively the world, linked by road networks and trains and planes and automobiles, and once a disease makes the jump, it suddenly has six billion people that it can potentially connect with."

Viruses represent living entities which are probably the least understood and perhaps the most important for humans," Wolfe said. A great deal needs to be learned about them. When it comes to actually forecasting disease, "We're really in the stone ages," much like, for example, the field of cardiology a half-century ago: "pretty much waiting for the heart attack to occur as opposed to trying to do prediction and prevention."

With the aid of new molecular tools and other scientific advances, researchers are developing the science of disease forecasting as they go, collecting data according to a standardized protocol developed in Wolfe's lab, which also serves as a central repository for the collection. Working with the contents of this "viral museum," as Wolfe describes it, scientists can analyze and catalog the diversity of microbial agents, characterize animal pathogens that might threaten humans in the future, and perhaps detect and control the emergence of a disease in humans before it can spread. "The science of disease forecasting is still in its infancy, but we're not going to wait until we have a perfect science," Wolfe said. "We need to go out there and start doing something about it now."

For more information, see Wolfe's Web site.