Autochthonous Chagas Disease: How Are These Infections Happening?

Proven cases of vector-transmitted acute autochthonous Chagas disease in the United States are rare (<10 cases). Possible or probable cases of unknown duration determined by serology are uncommon as well (<100). In Latin America it is widely accepted that after feeding, the kissing bug defecates and Trypanosoma cruzi in the feces is rubbed into the bite punctum. This is an inefficient method of parasite transmission. The average infected individual in Latin America suffers more than 1000 bites, but more importantly, there are often thousands of kissing bugs in a household dropping feces on the inhabitants and living quarters. Today in Brazil the most common form of acute Chagas is secondary to oral ingestion of the parasite in food and drink. We present our experience with many hundreds of individuals bitten by kissing bugs and the possibility of oral ingestion occurring in the United States.