Towards environmental detection of Chagas disease vectors and pathogen

Abstract

Chagas disease vector control relies on prompt, accurate identification of houses infested with triatomine bugs for targeted insecticide spraying. However, most current detection methods are laborious, lack standardization, have substantial operational costs and limited sensitivity, especially when triatomine bug densities are low or highly focal. We evaluated the use of FTA cards or cotton-tipped swabs to develop a low-technology, non-invasive method of detecting environmental DNA (eDNA) from both triatomine bugs and Trypanosoma cruzi for use in household surveillance in eastern Colombia, an endemic region for Chagas disease. Study findings demonstrated that Rhodnius prolixus eDNA, collected on FTA cards, can be detected at temperatures between 21 and 32 °C, when deposited by individual, recently blood-fed nymphs. Additionally, cotton-tipped swabs are a feasible tool for field sampling of both T. cruzi and R. prolixus eDNA in infested households and may be preferable due to their lower cost. eDNA detection should not yet replace current surveillance tools, but instead be evaluated in parallel as a more sensitive, higher-throughput, lower cost alternative. eDNA collection requires virtually no skills or resources in situ and therefore has the potential to be implemented in endemic communities as part of citizen science initiatives to control Chagas disease transmission.

Interrogating the transmission dynamics of Trypanosoma cruzi (Trypanosomatida, Trypanosomatidae) by Triatoma venosa (Hemiptera: Reduviidae) after the elimination of vector transmission by Rhodnius prolixus in Boyacá eastern Colombia

“…The detection of domestic and peridomestic transmission in areas certified as free from intradomiciliary transmission of T. cruzi should be a concern for vector control and public health agencies, considering T. venosa could be involved in the enzootic transmission into households, as described for T. dimidiata and T. maculata (Cantillo-Barraza et al, 2015;Hernandez et al, 2016;Velazquez-Ortiz et al, 2022). Therefore, our results highlight the need for a shift of these epidemiological scenarios throughout Latin America and adopt more sensitive tools that allow real-time identification of emerging foci (Cantillo-Barraza et al, 2015;Hernandez et al, 2016;Gysin et al, 2022). In Colombia, a primary deficiency is the lack of optimal infrastructure and trained personnel for Chagas disease molecular surveillance in departments and other decentralized entities responsible (WHO, 2007).…”

Artificial Feeding Systems for Vector-Borne Disease Studies

“…aegypti [ 107 ], Leishmania spp. infections in sandflies [ 108 , 109 , 110 ], xenomonitoring in tsetse flies [ 111 , 112 ], investigating Trypanosoma cruzi in triatomine bugs [ 113 , 114 , 115 ], and examining Yersinia pestis in fleas [ 116 ]. Hemotek feeders have the advantage of temperature control, standardization, and commercial availability [ 106 ].…”