Indicadores entomológicos e fontes alimentares de triatomíneos de uma área endêmica da doença de Chagas no semiárido brasileiro

Abstract

Worldwide, there are approximately 6 to 8 million people infected by the protozoan Trypanosoma cruzi, the etiological agent of Chagas Disease (CD), with approximately 4 thousand deaths/year in Brazil. Trypanosoma cruzi vectors are hematophagous triatomines, which have a wide variety of hosts, mainly domestic and wild mammals. The objective of this study was to understand the entomological indicators and food sources of triatomines captured in Petrolina, a municipality endemic for CD in Pernambuco, in the Brazilian semi-arid region. The entomological research was carried out from January to December 2022, both indoors (house/intradoimicile) and outdoors (vinicity/peridomicile). The household infestation index and the natural infection index were calculated. The Polymerase Chain Reaction (PCR) was performed to identify food sources, based on the sequencing of the 12S rDNA gene fragment, using vertebrate-specific primers. In total, 906 triatomines were captured in the peridomicile (807) and intradomicile (99), which were identified as Triatoma brasiliensis (84.7%, 767 specimens, 419 nymphs and 348 adults), T. pseudomaculata (14.7%, 133 specimens, 74 nymphs and 59 adults), Rhodnius nasutus (0.6%, 5 specimens, 4 nymphs and 1 adult), and T. sordida (0.1%, 1 adult specimen). The household infestation index was 11%. Of the 906 triatomines captured, 35 were infected by trypanosomatids, 33 of which were T. brasiliensis and two T. pseudomaculata, which corresponds to a natural infection index of 3.8%. The following food sources have been identified: humans on T. pseudomaculata (2) and T. brasiliensis (1); dog in T. brasiliensis (1) and rodent (Mus musculus) in T. brasiliensis (1). The results reinforce the need to intensify CD diagnosis, surveillance, and control actions in Petrolina, since an increase in entomological indices was recorded, in addition to the detection of human blood and domestic and synanthropic animals as a food source for triatomines infected, suggesting the risk of vector transmission of CD in the municipality. As it is a zoonosis, multidisciplinary and intersectoral CD surveillance actions must be carried out in the context of One Health approach.