'AIDS of the Americas' May Spread to U.S. with Climate Change

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In a splashily headlined editorial, the Public Library of Science has declared Chagas disease “The New HIV/AIDS of the Americas.” Sure enough, Chagas disease is exceptionally nasty. It's transmitted by blood-sucking, parasite-carrying insects, and it goes largely undetected until its victims suffer, and often die, from grossly enlarged hearts and intestines.

It's thought to have killed, among tens of millions of others, Charles Darwin. So how is a insect-borne, parasitically transmitted disease similar to the AIDS virus?

The New York Times explains: "Like AIDS, the authors say, Chagas disease has a long incubation time and is hard or impossible to cure. Chagas infects up to eight million people in the hemisphere, mostly in Bolivia, Mexico, Colombia and Central America. But more than 300,000 of the infected live in the United States, many of them immigrants." It can also be transmitted through blood transfusions, making for another parallel between the two killers.

All this amounts to some truly scary stuff—Chagas is, after all, easily transmissible, hard-to-cure, difficult-to-detect, and often fatal. And pharmaceutical companies haven't made tackling it a priority because it mostly impacts very poor people.

But it gets a little scarier still. As is the case with many other insect-borne diseases, climate change is expanding its range. Warming climes mean more viable stomping grounds for the bugs that carry the Chagas disease; typically those from the Reduviidae family, more commonly known as kissing bugs or assassin bugs. Science Daily reported just a couple months ago that researchers were turning up parasite-carrying, human-biting kissing bugs in the American Southwest—a hitherto unheard of occurrence:

Lori Stevens, a biologist at the University of Vermont, and her colleagues, found that 38 percent of the kissing bugs they collected in Arizona and California contained human blood. This upends the previous understanding of insect experts and doctors that the eleven species of kissing bugs that occur in the US don't regularly feed on people ...And more than 50 percent of the bugs the research team collected also carried Trypanosoma cruzi, the parasite that causes Chagas disease.

guachocat via Flickr/CC BY 2.0

Now, the American species of kissing bugs have behaved differently than the species causing the epidemic in Central and South America. According to researchers, this is primarily because the parasite gets transmitted when the bugs defecate—and southern kissing bugs eat and crap at the same time. Species native to the U.S. tend to hold off while eating, lowering the chances the disease-causing parasite will be transmitted. But climate change is bringing the more dangerous species northward.

"We know the bugs are already across the bottom two-thirds of the U.S., so the bugs are here, the parasites are here. Very likely with climate change they will shift further north and the range of some species will extend," Patricia Dorn, an expert on Chagas disease at Loyola University, told Science Daily.

The shift will come slowly, and researchers say the U.S. is better equipped to deal with the disease than our more tropical (and poorer) continental neighbors. But it's an unhappy prospect, and yet another ingredient to add to global warming's ever-lengthening recipe for civizational disaster. And hey, if the disease does start spreading on American shores, at least it might light a fire under Pfizer's ass to get to work on an affordable remedy. Silver linings, folks. They're important to consider when you're examining the prospective rise of the next climate change-abetted AIDS-scale epidemic.

Tags: Diseases | Global Climate Change | United States