Transmitted by bloodsucking kissing bugs, tropical Chagas disease—which afflicts millions in Central and South America—may affect more people in the U.S. than previously thought.
Although doctors officially have recorded only seven cases of new human infections in North America, a new study found that five of 13 kissing bugs collected from California and Arizona had bitten a human host—and many of the bugs they collected were infected with Chagas.
Chagas, aka American trypanosomiasis, is a cryptic foe. After a person becomes infected, early symptoms—fever, a swollen eye—may be mistaken for any number of other ailments. The disease earns its moniker, the “silent killer,” from its tendency to lie dormant in a person’s system for years, even decades, until striking the victim down, usually through sudden heart or digestive failure.
Currently, the U.S. is relatively unaffected by Chagas transmission—but the new study gives researchers pause. “The dogma is that bugs and humans are quite separate in the U.S.,” says Patricia Dorn, a molecular parasitologist at Loyola University New Orleans. “But now it seems that contact is not as rare as we thought,” she says.