PureInsight | August 25, 2003
[PureInsight.org] The world can expect more SARS-like outbreaks in the near future due to evolving cultural, environmental and economic conditions that provide viruses with new opportunities to infect humans, according to an expert on infectious disease and geographic medicine at the University at Buffalo.
"There's going to be another SARS (severe acute respiratory syndrome) sometime; there's no doubt about it," says Richard V. Lee, M.D., professor of medicine in the UB School of Medicine and Biomedical Sciences and an adjunct professor of anthropology.
"There are places in the world that seem to be a Pandora's box for certain kinds of infectious disease," explains Lee, who studies the health status of geographically isolated human populations. "The way people live and interact with their environment sets the stage for letting these viruses out of their box."
Some of these places, according to Lee, include fish-farming villages in Southeast Asia, where liver fluke infections, Japanese B encephalitis and Nipah virus threaten residents and agricultural communities in Africa that share boundaries with wildlife populations, where the Ebola virus and African tick typhus are active.
Lee, who has led UB medical student expeditions to treat people in remote areas in India, China, Kenya and Brazil, says the SARS outbreak was inevitable, as is the likelihood of outbreak for new and "old" viruses.
He calls the spread of SARS a classic example of how humans provide viruses, in this case, the coronavirus,with the opportunity to evolve into harmful human disease. Other examples include AIDS, which may have originated from human ingestion of infected gorilla meat, and monkey pox, which Lee says existed for decades as a primate disease in Africa before being transmitted to U.S. residents recently via Gambian giant rats and prairie dogs sold as exotic pets.
In the case of SARS, the densely populated region of Southern China, where people and farm animals live closely together, likely gave the coronavirus opportunity to jump back and forth among animal species before being passed on in new form to humans, Lee says.
The virus may have spread further when people ventured with their animals to marketplaces outside their home region, he speculates. Global air travel and crowded urban living spaces helped spread the disease to Hong Kong and North America.
"Humans can break a virus out of its Pandora box by moving the geography of the germ, or a virus can break out by switching to another species," Lee explains. "When we do things to a germ's environment we set the stage for the germs to do something to us."
SARS has not been eradicated, Lee notes. The virus that causes SARS still exists in animal species and is "looking for another opportunity" to infect humans, he says.
"As long as those hosts are alive and the bug stays in those hosts, the coronavirus will be around," Lee says. "It may evolve into a more benign bug or a more virulent bug, but it's not dead."
According to Lee, there are many viruses, like influenza, that are passed back and forth between humans and animals. As they're passed, their capacity to create disease changes over time. "These viruses go through all sorts of changes and when they emerge they may emerge as a very serious disease for humans," he says.
"Germs are smart and they do evolve."
Hand washing, Lee says, is one of the best defenses against the spread of disease. He cautions against the overuse of antiseptics, which could kill "good germs" that aid the body,in digestion, for example, and he says over-prescription of antibiotics could create drug-resistant viral strains.
"The fact that germs become resistant should not surprise anyone," Lee concludes. "They're in a constant state of guerilla warfare."