Project Summary. Chagas disease is emerging as an important neglected tropical disease in the southern United States. The disease is caused by an infection with the parasite Trypanosoma cruzi (T. cruzi), with the most common route of transmission being through the triatomine ?kissing bug? vector at the time of a blood meal. Approximately 20-30% of those infected with T. cruzi will go on to develop Chagas cardiomyopathy, which if left untreated will result in arrhythmias, progressive dilated cardiomyopathy, and ultimately death. We are finding mounting evidence of Chagas disease transmission within Texas; however, epidemiologic and clinical studies are severely lacking. Identification of Chagas cases is essential to: (1) improve clinical outcomes through treatment and monitoring of infection, (2) better understand the epidemiology and transmission dynamics of the disease, and (3) identify high risk populations to target for early screening, prevention, and intervention. At the National School of Tropical Medicine at Baylor College of Medicine in Houston, we have initiated studies to better define the epidemiology and burden of Chagas disease in Texas. Over the past year, we found 83/131 (63%) of triatomines collected from around the state to be positive for T. cruzi. Additionally, we began a pilot study involving recruitment of Chagas-positive blood donors from the regional blood bank. Of the 30 enrolled to date, 16 (53%) most likely acquired their infection in Texas, and interestingly, 38% of those individuals were avid hunters who mostly spent extended periods of time sleeping in tents, on the ground, or in make-shift shelters. During their interview, the hunters mostly stated they never used gloves when skinning and field dressing game. Considering up to 40% of wildlife are positive for T. cruzi, hunters can be at increased risk of exposure through contact with contaminated blood and organs as well as through sleeping outdoors in rural areas where insects are prevalent. The overall goal of this study is to understand the risk of Chagas disease in a potentially high-risk population of hunters. Our first objective will be to screen hunters for Chagas using the rapid testing kit at hunting conventions in five different regions of the state. We will then use a case-control study design to determine if certain environmental or exposure characteristics significantly put a person at higher risk for infection. We hypothesize that hunters will have a higher seroprevalence of infection when compared to overall state and national seroprevalence rates estimated from mandatory blood donor screening due to increased exposures to triatomine insects and direct contact with blood from wildlife reservoirs. The long-term goals of this study are to use the data derived from screening to identify high risk populations to target for prevention/intervention efforts. This high impact study will critically improve our understanding of Chagas disease in Texas.

R21AI112647

2016-06-01

2018-05-31