[Behavior of Lutzomyia longipalpis, the main vector of American visceral leishmaniasis, in Campo Grande, State of Mato Grosso do Sul]. / Comportamento de Lutzomyia longipalpis, vetor principal da leishmaniose visceral americana, em Campo Grande, Estado do Mato Grosso do Sul.

The municipality of Campo Grande, State of Mato Grosso do Sul, Brazil, has presented cases of canine and human visceral leishmaniasis since 2002, and is classified as an area of intense transmission. This study was carried out from May 2003 to April 2005, in partnership with the National Health Foundation and the State Health Department, with the objective of determining the behavior and seasonality of the species Lutzomyia longipalpis. Captures were accomplished using luminous traps of CDC type, at twelve stations distributed in the urban zone. The stations with the highest population densities were situated in the southern part of the city and the relative abundance increased during or immediately after rainfall. During the cold and dry months, the number of specimens was reduced and the relative abundance was higher in habitats surrounding homes. Spraying with alpha-cypermethrin at four-month intervals contributed towards reducing the vector numbers in three of the four sprayed stations. Among the eight stations that did not receive chemical interventions, five showed an increase.

Climatic factors and population density of Lutzomyia longipalpis (Lutz & Neiva, 1912) in an urban endemic area of visceral leishmaniasis in midwest Brazil.

The life cycle of vectors and the reservoirs that participate in the chain of infectious diseases have a strong relationship with the environmental dynamics of the ecosystems in which they live. Oscillations in population abundance and seasonality of insects can be explained by factors inherent in each region and time period. Therefore, knowledge of the relationship and influence of environmental factors on the population of Lutzomyia longipalpis is necessary because of the high incidence of visceral leishmaniasis (VL) in Brazil. This study evaluates the influence of abiotic variables on the population density and seasonal behavior of L. longipalpis in an urban endemic area of VL in Brazil. The sand fly captures were performed every two months between November, 2009 and November, 2010 in the peridomicile of 13 randomly selected residences. We captured 1,367 specimens of L. longipalpis, and the ratio of male/female flies was 2.86:1. The comparison of the total male specimens in the two seasons showed a statistical difference in the wet season, but there was no significant difference when considering the total females. With respect to climatic variables, a significant negative association was observed only with wind speed. During periods of high wind speeds, the population density of this vector decreased. The presence of L. longipalpis was found in all months of the study with bimodal behavior and population peaks during the wet season.