Diversity and interactions among triatomine bugs, their blood feeding sources, gut microbiota and Trypanosoma cruzi in the Sierra Nevada de Santa Marta in Colombia

Abstract

Chagas disease remains a major neglected disease in Colombia. We aimed to characterize Trypanosoma cruzi transmission networks in the Sierra Nevada de Santa Marta (SNSM) region, to shed light on disease ecology and help optimize control strategies. Triatomines were collected in rural communities and analyzed for blood feeding sources, parasite diversity and gut microbiota composition through a metagenomic and deep sequencing approach. Triatoma dimidiata predominated, followed by Rhodnius prolixus, Triatoma maculata, Rhodnius pallescens, Panstrongylus geniculatus and Eratyrus cuspidatus. Twenty-two species were identified as blood sources, resulting in an integrated transmission network with extensive connectivity among sylvatic and domestic host species. Only TcI parasites were detected, predominantly from TcIb but TcIa was also reported. The close relatedness of T. cruzi strains further supported the lack of separate transmission cycles according to habitats or triatomine species. Triatomine microbiota varied according to species, developmental stage and T. cruzi infection. Bacterial families correlated with the presence/absence of T. cruzi were identified. In conclusion, we identified a domestic transmission cycle encompassing multiple vector species and tightly connected with sylvatic hosts in the SNSM region, rather than an isolated domestic transmission cycle. Therefore, integrated interventions targeting all vector species and their contact with humans should be considered.

Estimating the genetic structure of Triatoma dimidiata (Hemiptera: Reduviidae) and the transmission dynamics of Trypanosoma cruzi in Boyacá, eastern Colombia

“…maculata with 11 and R . prolixus with 9, sharing Homo sapiens , Canis , Felis , Bos , Sus , Didelphis , and Metachirus [ 63 ], herein identified as well ( S4 Fig ). These results imply that T .…”

“…These results imply that T . dimidiata ’s feeding behavior is highly similar to other successful vectors, evidencing a parasite’s transmission cycle encompassing the broadest range of hosts and vectors that do not support a strict domestic/sylvatic transmission cycle [ 63 ]. This highlights the importance of T .…”

“…Regarding the DTUs, TcI was the only found, as reported before, in T . dimidiata [ 63 , 64 ]. With the NGS strategy, TcIb was the most common, its presence has been confirmed in Colombia, Costa Rica, and Mexico before ( Fig 3B ) [ 62 ].…”

Towards environmental detection of Chagas disease vectors and pathogen

“…In addition to field standardization, longitudinal evaluations of this methodology are needed alongside parallel TMCs and community serosurveys, to quantitatively evaluate this technique, to establish the true LoD of parasite/vector eDNA in the field using both FTA cards and cotton-tipped swabs, to determine how seasonal changes in triatomine population dynamics affect eDNA degradation and to optimise timing and logistics of eDNA wall sampling. While this study only investigated presence/absence of T. cruzi and R. prolixus , further research is warranted to assess the possibility of using recovered eDNA for community-wide blood-meal analysis, surveillance of molecular insecticide resistance and characterization of parasite and vector population genetic structures, including reinfestation dynamics after insecticide spraying campaigns 13 , 17 , 67 . These aspects are pivotal to the development of effective vector control programmes in Chagas disease endemic regions.…”

Triatomine Raubwanzen als Überträger der Chagas-Krankheit : Verbreitung und Vektor-Pathogen-Interaktion

“…A difference in the microbiota composition of triatomines on a taxonomic level between infected and non-infected insects has rarely been demonstrated before [85]. However, taking into account the overall bacterial diversity, Díaz, et al [79] showed that T. cruzi-challenged insects bare a more diverse bacterial community than the control group.…”