Preliminary Characterization of Triatomine Bug Blood Meals on the Island of Trinidad Reveals Opportunistic Feeding Behavior on Both Human and Animal Hosts

Abstract

Chagas disease is a neglected tropical disease caused by infection with Trypanosoma cruzi. The parasite is endemic to the Americas, including the Caribbean, where it is vectored by triatomine bugs. Although Chagas disease is not considered a public health concern in the Caribbean islands, studies in Trinidad have found T. cruzi-seropositive humans and T. cruzi-infected triatomine bugs. However, little is known about triatomine bug host preferences in Trinidad, making it difficult to evaluate local risk of vector-borne T. cruzi transmission to humans. To investigate this question, we collected triatomine bugs in Trinidad and diagnosed each one for T. cruzi infection (microscopy and PCR). We then carried out a blood meal analysis using DNA extracted from each bug (PCR and sequencing). Fifty-five adult bugs (54 Panstrongylus geniculatus and one Rhodnius pictipes) were collected from five of 21 sample sites. All successful collection sites were residential. Forty-six out of the 55 bugs (83.6%) were infected with T. cruzi. Fifty-three blood meal hosts were successfully analyzed (one per bug), which consisted of wild birds (7% of all blood meals), wild mammals (17%), chickens (19%), and humans (57%). Of the 30 bugs with human blood meals, 26 (87%) were from bugs infected with T. cruzi. Although preliminary, our results align with previous work in which P. geniculatus in Trinidad had high levels of T. cruzi infection. Furthermore, our findings suggest that P. geniculatus moves between human and animal environments in Trinidad, feeding opportunistically on a wide range of species. Our findings highlight a critical need for further studies of Chagas disease in Trinidad in order to estimate the public health risk and implement necessary preventative and control measures.