Avaliação do risco entomológico da doença de Chagas na macrorregião leste de Minas Gerais, Brasil

Abstract

Chagas disease remains one of the major public health problems in Latin America, where the majority of individuals affected by this endemic disease are concentrated. Following advances in vector-borne transmission control in recent years, epidemiological surveillance has focused its actions on controlling species previously considered of secondary importance, as they continue to invade households and exhibit high rates of natural infection by T. cruzi. The objective of this study was to evaluate the entomological risk of Chagas disease in municipalities of the eastern macro-region of Minas Gerais, from 2020 to 2023. This is a longitudinal study in which insects captured by residents of the region were sent to the Parasitology Laboratory of UFJF/GV, where they were identified in relation to their feeding habits and, when hematophagous, differentiated according to species, capture location, and infection by T. cruzi, generating a database. Based on this information, thematic maps of the spatial distribution of species and natural infection by T. cruzi were created, in addition to a categorization for the municipalities, considering the entomological risk (proximity) between triatomines and humans. Of the 558 insects captured and sent to the laboratory, 439 (78.7%) were triatomines, 60 (10.7%) were predators, and 59 (10.6%) were phytophagous. Among the triatomines, the following vector species were found: Panstrongylus megistus (n=210), Triatoma vitticeps (n=180), Panstrongylus diasi (n=44), Rhodnius neglectus (n=2), Triatoma pseudomaculata (n=1), Rhodnius domesticus (n=1), and Cavernicola pilosa (n=1). Most of these captures were carried out inside homes (68.6%). The average natural infection rate was 34.9%. Among the infected triatomines, 81.2% were located indoors, and the seasonality of triatomine captures showed a higher concentration in the last months of the year, specifically September, October, and November. Thematic maps of vector species distribution showed a larger spatial distribution area for the species T. vitticeps, followed by the species P. megistus, found mainly in the Peçanha microregion. Regarding risk categorization, 27 municipalities were classified as risk levels 4, 5, or 6, indicating that the protozoan's life cycle is maintained in these locations. The data demonstrate a considerable entomological risk for Chagas disease in the Eastern Macroregion, where vector species are widely dispersed, with high infection rates of Trypanosoma cruzi, especially in indoor environments. These results reveal a close proximity between the captured triatomine species and humans, which may suggest the occurrence of possible silent transmissions. Therefore, these data reinforce the need to intensify and improve entomological and epidemiological surveillance actions in the region, aiming to prevent vector-human contact.