An interesting study by the University of Arizona came out earlier this year:
The researchers collected triatomine bugs (the vector for Chagas disease) in and around human houses in Tucson and checked to see how many of them carried the protozoa that causes Chagas disease, Trypanosoma cruzi. They found that at 63% of the collection sites (14 out of 22) there was at least one infected specimen, and 41.5% of all the bugs were infected.
So, are there a lot of cases of Chagas disease in Arizona?
No. NPR recently reported that neglected tropical diseases, like Chagas, take an underappreciated toll in the U.S., but most of these cases originate in other parts of the world. There are only 7 known autochthonous cases in the U.S. (meaning, the disease was definitely acquired within the U.S.), and none of these were in Arizona .
So, why aren’t there any reported cases of Chagas disease in Arizona?
A partial explanation is that there is better housing in Arizona than in Latin America, so it is harder for the kissing bugs to get into homes and bite people in their sleep. But the main reason we don’t find any cases of Chagas in Arizona is the species of the kissing bug. Most kissing bugs in Arizona are Triatoma rubida, and after they take a blood meal, they wait a bit before defecating. The kissing bugs in the Chaco are Triatoma infestans, and they ‘shit where they eat’, making it easier for the parasite they carry to get into the bite wound.
The good health of Arizonans is mostly due to the toilet habits of an insect.
This is the website for The Kissing Bug Project.