What is it about?
In the semi-arid region of northeastern Brazil, Triatoma brasiliensis is the main Chagas disease vector. This insect has been studied molecularly by several approaches. We discovered an intimate relationship among Triatoma brasiliensis, rodents of the Caviidae family, and Trypanosoma cruzi - the parasite that causes Chagas disease. Whereas the rodent Kerodon rupestris is the main reservoir of T. cruzi in the wild environment, the other synanthropic - Galea spixii - is the reservoir in the anthropic (man-made) environments. The eco-epidemiological implications of this tripartite association are discussed in the study.
Photo by Vitor Paladini on Unsplash
Why is it important?
The findings were passed on to those in charge of public health surveillance and could help design vector control measures to avoid Chagasic outbreaks and sporadic infections.
Read the Original
This page is a summary of: Dynamics of food sources, ecotypic distribution and Trypanosoma cruzi infection in Triatoma brasiliensis from the northeast of Brazil, PLoS Neglected Tropical Diseases, September 2020, PLOS, DOI: 10.1371/journal.pntd.0008735.
You can read the full text:
Dynamics of food sources, ecotypic distribution and Trypanosoma cruzi infection in Triatoma brasiliensis from the northeast of Brazil
Innovative approaches used to combat Chagas disease transmission tend to combine a set of comprehensive efforts to understand the ecology of local vectors. In this work we identified molecularly the blood meal of 181 Triatoma brasiliensis, distributed in 18 populations (8 sylvatic and 10 peridomestic), which were collected across a range of 240 km (East-West) and 95 km (North-South) in the semi-arid region of northeastern, Brazil. We used the vertebrate mitochondrial gene (cytochrome B) sequencing applied to DNA isolated from bug midgut to identify the insect blood meal sources via the BLAST procedure. The peridomestic populations were classified according to two main hypotheses of site-occupancy for T. brasiliensis: the first says that the infestation is mainly driven by structures that resemble its natural habitat (stony-like ecotopes) and the second assumes that it is associated with key-hosts (rodents and goats). Rodents of the Caviidae family (Galea spixii and Kerodon rupestris) were identified as the key-host of T. brasiliensis, but also the potential Trypanosoma cruzi reservoir–able to connect the sylvatic and domestic T. cruzi cycle. Cats also deserve to be studied better, as potential T. cruzi reservoirs. By modeling the food sources + site-occupancy + T. cruzi natural infection, we identified man-made ecotopes suitable for forming dense triatomine infestations with high rates of T. cruzi natural infection, which may be taken into account for vector control measures.
Bilateral cooperation (UNICAMP-CNRS) to optimize ongoing studies on vectors molecular eco-epidemiology
Authors received grants from Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), grant 16/08176-9, designated Young Investigators Award. The continued collaboration between Brazilian and French Institutions was supported by bilateral cooperation between FAPESP and CNRS, grant 17/50329-0. The funder had no role in study design, data collection and analysis, the decision to publish, or the preparation of the manuscript.
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