Trypanosoma cruzi testing of Triatoma vectors in a likely endemic area of Southeast Texas

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 DESCRIPTION (provided by applicant): Chagas' disease (Trypanosoma cruzi infection) transmission occurs between a mammalian host and a triatomine insect vector. Acute disease in humans is normally nonspecific and mild; however, approximately 20-30% of those infected with the parasite will go on to develop cardiomyopathy, characterized by conduction system abnormalities, progressive dilated cardiomyopathy, and ultimately death. Early diagnosis is critical for initiating treatment to prevent irreversible fibrosis and improve health outcomes. In he southern United States, we are finding mounting evidence of autochthonous disease transmission between infected vectors and humans. Texas has the highest number of locally acquired human cases. In fact, the first geographic clustering of locally acquired human cases in the United States was identified in the city of Houston, Texas. Additionally, this city has a substantial veterinary disease burden, particularly among shelter dogs. Historical studies dating back to 1987 support a continuous landscape of disease transmission in this potentially endemic area. Unfortunately, epidemiologic studies of the vector are severely lacking, and the true burden of disease has not been fully elucidated in this area. This current proposal aims to collect and test local vectors for infection, clarify local vector species, and perform blood meal analysis to determine host preferences. Identification of Trypanosoma cruzi infected vectors is essential to (1) prevent disease transmission, (2) better understand the epidemiology of the disease, and (3) identify high risk populations to target for screening and intervention. This innovative pilot project will be the first to assess Trypanosoma cruzi infection prevalence among triatomine vectors in Houston, the nation's 4th largest city, to better ascertain disease burden and risk to residents. The overall goal of this study is to identify areas of positive Trypanosoma cruzi vectors and assess the risk of disease transmission to humans. We hypothesize that half of collected vectors will be infected and that blood meal analysis will indicate domestic mammals and humans as the most prevalent meal source. This project will foster new collaborations between resident epidemiologists with expertise on human Chagas disease and expert entomologists with a long history of handling vectors of medical importance in the region. The long-term goals of this study are to establish vector surveillance capacity in a potentially endemic area and to develop effective public health campaigns targeted for residents living in high-risk areas for transmission. This high impact study will critically impact our understanding of Chagas disease transmission factors in Texas, with an opportunity to identify high risk populations for targeted prevention and intervention efforts.