Brainstorming with Paul Ewald - How Disease Evolves

Brainstorming with Paul Ewald - How Disease Evolves

"BRAINSTORMING WITH PAUL EWALD
How Disease Evolves
By David Stipp, Tuesday, May 3, 2005 FORTUNE

Back when he was a grad student in 1977, Paul Ewald came down with an intestinal bug. He'd been doing research at the University of Washington at Seattle on the social behavior of sparrows. But the microbes making him sick proved more interesting. Lying in bed, he wondered, What is diarrhea good for? 'I started thinking maybe it is a defense mechanism by the body to get rid of an infectious agent,' he recalls. 'But in an argument with myself, I realized that it might be due to a microbe manipulating my body in order to spread itself.' In other words, diarrhea might be a microbe survival strategy - a way for it to find fresh victims through contamination of hands, objects, and water supplies.

That startling thought eventually led Ewald, now a professor at the University of Louisville, to abandon sparrows and help pioneer a branch of medicine that analyzes disease from the perspective of evolutionary biology. The Darwinians aren't well known among physicians, but they've shed light on many medical riddles, such as why hospital-acquired infections are so deadly. They've also chipped away at stone-writ wisdoms: When you're prescribed antibiotics, it may not always pay to take all of them. Popping painkillers for a sprained ankle could hurt you. And we should probably be a lot more scared of hepatitis C than emerging killers like bird flu."

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