Trypanosoma cruzi prevalence and genetic strain diversity in kissing bug vectors (Triatoma spp., Reduviidae) across the southern United States

Trypanosoma cruzi is a protozoal parasite transmitted by triatomine bugs (Triatoma spp., Reduviidae). Triatoma spp. are prevalent throughout the tropical and subtropical regions of the Americas, where the parasite causes Chagas disease in animals and humans. Although T. cruzi is also harbored in wildlife, domestic animals, and Triatoma spp. throughout the southern U.S., the public health burden of disease is not recognized to be as high as it is in Central and South America.  We hypothesize that geographic variation in parasite genetic strains may contribute to the variation in disease burden. To begin to address this hypothesis, we initiated sampling of vectors across central Texas in spring 2013.  Our vector sampling is two-fold and includes (i) black light collections and manual searches from diverse ecoregions and (ii) solicitation of bugs from the public across the southwestern United States using a citizen science approach.  Following dissection of the bug intestinal tract and DNA extraction, we are assessing T. cruzi infection prevalence and strain diversity over space and time based on the amplification of a single polymorphic locus (TcSC5D; a gene from the sterol biosynthesis pathway of T. cruzi). Here, we present data covering bug phenology, T. cruzi genetic strain type, and molecular identification of triatomines across the southwestern United States.  We expect that our studies of the ecology of the disease system and parasite strain types in vector populations will provide critical information to predict and reduce T. cruzi infection in human and animal populations.