(10 of 10)
Then there are the scourges that have always been with us, the Legionnaire's bacteria that suddenly find an environment in which to flourish anew momentarily, or the influenza virus that undergoes minor mutations to spring forth with renewed vigor. Indeed, of all the potential disease agents looming on the horizon, it is the familiar flu virus that worries Foege the most. "I fully anticipate that possibly in our lifetime we will see another flu strain that is as deadly as 1918. We have not figured out good ways to counter that." The same holds for the most common of bacteria and viruses, like the staphylococcus, which are adept at evolving into new forms.
"Just a few years ago, in an excess of hubris, I predicted we were nearly finished with the problem of infection," Dr. Lewis Thomas, noted biologist and prize-winning author (The Lives of a Cell), observed recently. "I take it back." Through the heroic struggle of medical sleuths, most diseases faced today can be controlled, as some day AIDS will be. But microbes, which have existed on this planet far longer than man, show no signs of being unconditionally conquered. Amid the billions that exist harmoniously around us, there will always be some that become unexpectedly disruptive, mysteriously virulent. Said Thomas: "There is a lot more research to be done, not just about AIDS but into infectious diseases in general. We have not run out of adversaries, nor is it likely we will do so for a long time to come." Thus the disease detectives must keep pounding the pavement, peering through microscopes, asking their questions.
—By Walter Isaacson.
Reported by Joseph N. Boyce/Atlanta and Peter Stoler/Washington, with other bureaus
* The classic definition of an epidemic is an outbreak of disease affecting 1% of the population. But most doctors now agree on a newer criterion and declare an epidemic whenever the incidence of a disease rises above its normal "background level," or rate of natural occurrence.