Characterization of the sand fly fauna in Barbalha, one of the municipalities with the highest leishmaniasis rates in Brazil.

Leishmaniases are a complex of sand fly-borne diseases that are considered a public health issue in several countries. Brazil presents high leishmaniases rates. The South of Ceará State, known as Cariri region, shows worrying statistics mainly on American tegumentary leishmaniasis. In Barbalha, which is one of the municipalities in this region, there is still a lack of studies regarding the local phlebotomine (Diptera: Psychodidae) fauna in order to help clarify the high rates. This study aimed to characterize such fauna by capturing sand flies with light traps during a four-year period. A total of 3730 sand flies were captured, of which 37.8% were females. Fourteen species were found: 13 of the Lutzomyia genus and one of the Brumptomyia genus. Of the Lutzomyia species, four were proven and five had potential involvement in leishmaniasis transmission. Lutzomyia longipalpis was the most common species (66.97%). This predominance, especially in the urban area, indicates its epidemiological importance and adaptation to environmental conditions modified by human activity. In fact, further studies are still required to accurately determine the behavioral features of these vectors in order to guide public health measurements towards its control and prevention.

Sand fly (Diptera, Psychodidae, Phlebotominae) abundance and diversity in areas affected by the São Francisco River transposition project in Ceará State, Brazil.

BACKGROUND: Entomological surveillance of sand fly vectors was carried out to support leishmaniasis prevention and control measures in areas affected by the São Francisco River Transposition Project. METHODS: Sand flies were collected monthly between May 2011 and December 2014 in seven municipalities: Missão Velha, Brejo Santo, Lavras da Mangabeira, Iguatu, Mauriti, Jaguaribe and Jaguaretama, in dwellings, peridomicile and forest areas for three consecutive days, for a period of 12 h each day (18:00 to 06:00 h). Differences in species composition between sites were tested with Shannon's diversity index, the similarity between habitats was estimated by the Sørensen's qualitative similarity index and, for the most abundant species in each municipality, a standardized index of species abundance was applied. The influence of climatic factors on sand fly population densities was analyzed using Spearman's correlation coefficients. RESULTS: A total of 214,213 sand fly specimens belonging to 18 species were captured. The most abundant species in all municipalities was Lutzomyia longipalpis (Lutz & Neiva, 1912). The municipalities of Mauriti and Missão Velha stand out in terms of high species richness, with the latter exhibiting the greatest diversity. The number of sand flies in the Iguatu, Jaguaribe and Jaguaretama municipality was higher during the rainy months, whereas the populations declined in the drier months; the sand fly population density in other municipalities (Missão Velha, Brejo Santo, Lavras de Mangabeira and Mauriti) showed negative correlation with rainfall. CONCLUSIONS: This study confirms the presence of several Leishmania spp. vectors in the seven municipalities affected by the São Francisco River Transposition Project, with Lu. longipalpis being the most abundant species at all study sites. Vector populations in these municipalities should be monitored, ultimately to assess the associations between environmental changes and sand fly population dynamics and leishmaniasis transmission risk.