Potential Vectors of Leishmania Parasites in a Recent Focus of Visceral Leishmaniasis in Neighborhoods of Porto Alegre, State of Rio Grande do Sul, Brazil

Abstract

Abstract In view of recent cases of human and canine visceral leishmaniasis reported in Porto Alegre, Rio Grande do Sul, Brazil, we investigated the sand fly fauna inhabiting the neighborhoods of Morro Santana and Jardim Carvalho, Brazil, continuing a series of entomological surveys aimed to identify potential vectors of Leishmania (Ross, 1903) parasites. Sand flies were collected monthly from October 2016 to October 2017 using CDC light traps in the intradomiciliary and peridomiciliary environments of seven residences. Sand fly abundance was correlated to climatic variables. Females were pooled by species, location, and date for Leishmania DNA molecular screening using ITS1 and kDNA polymerase chain reaction. In total, 501 sand flies from five species were collected in which Lutzomyia gaminarai (Cordero, Vogelsang & Cossio, 1928) (Diptera: Psychodidae) (78%) was the most abundant species in the intradomiciliary sites while Migonemyia migonei (Franca, 1920) (Diptera: Psychodidae) (43.3%) was the most abundant in the peridomiciliary sites. A higher number of sand flies were collected during the warmest months, from December to March (Mann–Whitney statistical test – P < 0.001). Leishmania infantum DNA was detected in Lu. gaminarai (2), Pintomyia fischeri (Pinto, 1926) (1) and Mg. migonei (1). Leishmania braziliensis DNA was detected in Lu. gaminarai (1) and Pi. fischeri (1). Our results add support to the possible vector role of Pi. fischeri in the epidemiological cycle of Le. infantum in Brazil. Furthermore, the first documented detection of Leishmania DNA in Lu. gaminarai may be indicative of multiple vectors being involved in the Leishmania cycle within Porto Alegre.