America’s War on the Kissing Bug

Excerpt: If Thomas Cropper, a public-health veterinarian at Lackland Air Force Base, in San Antonio, Texas, thought about Chagas disease at all, he thought about it as a Central and South American problem. Named after the Brazilian physician who described it, in 1909, Chagas is a classic—one might say egregious—example of a neglected tropical disease. It is caused by the protozoan parasite Trypanosoma cruzi, which is delivered to its host by kissing bugs, known formally as triatomines. The bugs are bloodsuckers—their nickname comes from their penchant for biting near the eyes or mouth—and they can swell to the size of grapes as they feed, causing them to defecate and leave the parasite behind to make its way into the host’s bloodstream. A gross and not particularly efficient mode of transmission, it’s still good enough to have kept Chagas going since pre-Columbian times. According to the World Health Organization’s shifting estimates, between six and seven million people in Latin America are currently infected. If you’re infected but don’t have symptoms, you’re likely to find out only after donating blood. If you do have symptoms, you’re probably in trouble. About a third of Chagas patients develop a chronic form that leads to heart damage and failure.