Spatial distribution of triatomines in domiciles of an urban area of the Brazilian Southeast Region

Abstract

Reports of triatomine infestation in urban areas have increased. We analysed the spatial distribution of infesta-tion by triatomines in the urban area of Diamantina, in the state of Minas Gerais, Brazil. Triatomines were obtainedby community-based entomological surveillance. Spatial patterns of infestation were analysed by Ripley?s K func-tion and Kernel density estimator. Normalised difference vegetation index (NDVI) and land cover derived from sat-ellite imagery were compared between infested and uninfested areas. A total of 140 adults of four species were cap-tured (100 Triatoma vitticeps, 25 Panstrongylus geniculatus, 8 Panstrongylus megistus, and 7 Triatoma arthurneivaispecimens). In total, 87.9% were captured within domiciles. Infection by trypanosomes was observed in 19.6% of 107examined insects. The spatial distributions of T. vitticeps, P. geniculatus, T. arthurneivai, and trypanosome-positivetriatomines were clustered, occurring mainly in peripheral areas. NDVI values were statistically higher in areasinfested by T. vitticeps and P. geniculatus. Buildings infested by these species were located closer to open fields,whereas infestations of P. megistus and T. arthurneivai were closer to bare soil. Human occupation and modificationof natural areas may be involved in triatomine invasion, exposing the population to these vectors.