Kissing Bugs Harboring Trypanosoma cruzi, Frequently Bite Residents of the US Southwest But Do Not Cause Chagas Disease

Low Trypanosoma cruzi transmission risk to humans in the Trans-Pecos region of Texas

“…This study highlights the nearly 40 years of high risk exposure to known Trypanosoma cruzi- infected triatomines from the Trans-Pecos region, along with a lack of CD transmission to humans. Results are consistent with previous data in an analogous ecological setting in Arizona ( Behrens-Bradley et al, 2019 ). Triatomine transmission of Trypanosoma cruzi to humans depends on post bloodmeal defecation behavior, number of human exposures, and vector parasite load ( Klotz et al, 2016 ).…”

“…Despite substantial infection in triatomines and mammalian reservoirs, results of this study suggest individuals in this area of Texas are not at high risk for contracting CD. Similar results were identified in southern Arizona, a comparable desert climate with great insect exposure but low levels of human infection ( Behrens-Bradley et al, 2019 ).…”

“…CD is a parasitic infection that leads to irreversible heart damage and death in 20–30% of human cases ( Bern et al, 2011 ). Inadequate surveillance and physician knowledge make it difficult to determine the true burden of autochthonous infection in the US, despite consistent reports of domestic invasion and anaphylaxis resulting from triatomine bites in the southwest ( Behrens-Bradley et al, 2019 ; Garcia et al, 2015 ; Stimpert and Montgomery, 2010 ; Klotz et al, 2016 ). This investigation focuses on an area in Texas with a long history of human bites, unexplored transmission dynamics, and unknown human infection prevalence ( Garcia et al, 2015 ).…”

History of indigenous Trypanosomacruzi infection in humans, animals and triatomines in California, USA

“…Studies describing the epidemiology of Chagas disease and ecology of triatomine vectors in the USA have been focused mainly in Texas, where high rates of T. cruzi-infected triatomines and occasionally human cases have occurred (Garcia et al, 2016;Gorchakov et al, 2016;Sarkar et al, 2010). Interestingly, studies in similar ecological habitats like Arizona have shown low human infection juxtaposing high triatomine infection rates, despite prolonged periods of repeated human exposure (Behrens-Bradley et al, 2020;Bern et al, 2011). Relative to Texas, few studies have examined the history of human-triatomine interactions and potential transmission risk of T. cruzi in neighbouring states with similar climates like New Mexico, Arizona and California.…”

Autochthonous Chagas Disease in the United States: How Are People Getting Infected?

“…A study conducted in Arizona has shown that despite a high proportion of kissing bugs being infected with T. cruzi (> 50%) and residents frequently being bitten, none had confirmatory serologic evidence of Chagas disease. 21 Nonetheless, a likely autochthonous case was isolated from a young woman from southern Arizona who did not recall being bitten by kissing bugs but tested positive for T. cruzi infection at blood donation. Further investigation yielded T. cruzi-positive kissing bugs at her residence.…”