The transmission of visceral leishmaniasis in the municipality of Guarujá, on the Coast of São Paulo state, Brazil

ABSTRACT OBJECTIVE To perform an entomological survey, evaluating the circulation of Leishmania spp. in sand flies captured from the new foci of visceral leishmaniasis (VL) in the coastal region of São Paulo state. METHODS Sand flies were captured from November 2016 to September 2018 using light traps of the Centers for Disease Control (CDC), in the neighborhood where VL cases were reported. Leishmania spp. circulation was evaluated by gut dissection and molecular analysis of the females captured. RESULTS Nyssomyia intermedia was the more frequent species (90,7%) within the 1,203 sand flies captured. We found no flagellates in dissected females, but two pools containing females of Ny. intermedia presented DNA of L. infantum. CONCLUSION Our results suggest that Ny. intermedia might be involved in the establishment of this new VL focus in Sao Paulo. However, before incriminating this species as a L. infantum vector, further studies should investigate other vectorial capacity parameters, including competence, survival, and feeding habits.

Natural infection of Lutzomyia longipalpis (Cembrene-1 population) with Leishmania infantum in a new visceral leishmaniasis focus in the eastern region of São Paulo State, Brazil

Abstract INTRODUCTION Visceral leishmaniasis (VL) transmission has been associated with two different populations of the Lutzomyia longipalpis complex in São Paulo state. METHODS In a recent focus of VL, we captured and dissected sand flies and investigated Leishmania infantum infection by parasitological, PCR, and sequencing analysis. RESULTS Flagellates were observed in 2 of 47 (4.2%) cembrene-1 Lu. longipalpis females. The sequences obtained matched those of Le. infantum. CONCLUSIONS We found that the transmission of Le. infantum by cembrene-1 females may occur at a high rate in this focus of VL and presented new data on the vector capacity of this population.

Leishmaniose visceral americana: avaliação dos parâmetros da capacidade vetorial de Lutzomyia longipalpis em área urbana do muncípio de Panorama, São Paulo, Brasil / American Visceral Leishmaniasis evalutation of parameters related to the vectorial capacity of Lutzomyia longipalpis in the urban area of Panorama municipality, São Paulo state, Brasil

Introdução: A leishmaniose visceral (LV) é um importante problema de saúde pública no Brasil, com cerca 3000 mil casos notificados anualmente. Nos últimos anos, a LV tem ampliado sua distribuição em vários estados do país, associada principalmente aos processos socioambientais, antrópicos e migratórios. A LV é causada pela infecção com Leishmania infantum chagasi, transmitida, principalmente, por Lutzomyia longipalpis (Diptera: Psychodidae). Este flebotomíneo apresenta ampla distribuição nas Américas, todavia, evidências sugerem que se constitui em um complexo de espécies crípticas. A dinâmica de transmissão da LV é modulada por fatores ecológicos locais que influenciam a interação entre populações do patógeno, do vetor e dos hospedeiros vertebrados. Portanto, o estudo das variáveis associadas a esta interação pode contribuir para elucidar aspectos dos elos epidemiológicos e contribuir para a tomada de decisões em saúde pública. Objetivo: Avaliar parâmetros relacionados à capacidade vetorial da população de Lu. longipalpis presente em área urbana do município de Panorama, estado de São Paulo. Métodos: Foram realizadas capturas mensais durante 48 meses para avaliar a distribuição espaço-temporal de Lu. longipalpis e investigar a circulação de Le. i. chagasi

Introduction: Visceral leishmaniasis (VL) is an important public health problem in Brazil, where annually about 3000 cases are notified. In the later years VL has spread through some states, associated mainly to environmental, anthropic and migratory process. Visceral leishmaniasis is caused by the infection with Leishmania infantum chagasi transmitted by the sand fly species Lutzomyia longipalpis (Diptera: Psychodidae). This species have a broad distribution in the Americas, however, there are evidences suggesting that it constitutes a cryptic species complex. The VL transmission dynamic is modulated by focal ecological factors that influence the pathogen-vector-host interactions. Thus, the analyses of variables associated to this interaction could contributes to elucidate the epidemiological links and to the public health decision-making. Objective: To evaluate parameters related to the vectorial capacity of Lutzomyia longipalpis in the Panorama municipality, São Paulo state, Brazil. Methods: Monthly captures of sand flies were undertaken during 48 months to evaluate the spatial and temporal distribution of Lu. longipalpis and its natural infection with Le. i. chagasi. Experiments of capture-mark-release-recapture to estimate the population survival, the gonotrophic cycle duration and the attractiveness of the most frequent host to Lu. longipalpis were also performed