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.

Estudos da fauna flebotomínica (Diptera: Psychodidae: Phlebotominae) e infecção natural por Leishmania infantum em municípios da região noroeste do estado de São Paulo, Brasil / Studies on the phlebotomine sandflies fauna (Diptera: Psychodidae: Phlebotominae) and on the natural infection by Leishmania infantum in municipalities of northwest region of the State of São Paulo

A expansão geográfica e o crescente aumento dos casos de leishmaniose visceral na região noroeste do estado de São Paulo despertaram o interesse em desenvolver estudo para identificar a fauna flebotomínica e avaliar sua infecção natural por Leishmania infantum nos municípios de Fernandópolis, Santa Fé do Sul e Votuporanga. Foram realizados inquéritos entomológicos com a utilização de armadilhas luminosas do tipo CDC, instaladas em diferentes ecótopos peridomiciliares, durante o período de agosto de 2013 a novembro de 2014. A detecção de DNA de L. infantum em flebotomíneos foi realizada por meio da Reação em Cadeia da Polimerase (PCR). Foram coletados 507 flebotomíneos, sendo 116 fêmeas (22,9 %) e 391 machos (77,1 %), representados por sete espécies, com predomínio de Lutzomyia longipalpis, com 461 exemplares (90,9 %). As análises moleculares revelaram DNA de L. infantum em um exemplar de L. longipalpis capturado em Fernandópolis. Estes resultados confirmam a presença desta espécie nos municípios pesquisados. E o encontro de pelo menos um exemplar, naturalmente infectado, em Fernandópolis evidencia a necessidade de realizar ações de controle direcionadas aos vetores neste município, com o intuito de conter sua dispersão e prevenir a ocorrência de casos humanos de leishmaniose visceral.

The geographical expansion and the increase of visceral leishmaniasis cases in northwest region ofthe São Paulo state aroused the interest of conducting a study to identify the phlebotomine sandfliesfauna, and to evaluate the rate of natural infection by Leishmania infantum in Fernandópolis, SantaFé do Sul and Votuporanga. Entomological surveys were conducted using the CDC miniature lighttraps, installed in different types of peridomestic ecotopes, during the period from August 2013 toNovember 2014. The L. infantum DNA detection in phlebotomine sandflies was performed by meansof conventional Polymerase Chain Reaction (PCR). Five hundred seven phlebotomine sandfliesspecimens were collected, being 116 females (22.9 %) and 391 males (77.1 %), which were representedby seven species, prevailing Lutzomyia longipalpis, with 461 specimens (90.9 %). Molecular analysisrevealed DNA of L. infantum in one specimen of L. longipalpis from Fernandópolis. These findingsconfirm the occurrence of this species in all of the surveyed municipalities. And the existence ofat least one specimen, naturally infected in Fernandópolis, highlights the need for performing thefurther control measures directed to the vectors in this municipality, for restraining their spread andto prevent the occurrence of human cases of visceral leishmaniasis.