Phlebotomine sand flies in Porteirinha, an area of American visceral leishmaniasis transmission in the State of Minas Gerais, Brazil

Abstract

A study of the phlebotomine sand fly fauna was carried out in an endemic area of American visceral leishmaniasis (AVL) in the municipality of Porteirinha, in the Brazilian state of Minas Gerais. Captures were performed with CDC light traps in 7 districts, 5 days per month, during 2 consecutive years (January 2000 to December 2001). A total of 3240 sand flies were captured and identified. Sixteen species were found, among which 15 belonged to the genus Lutzomyia and one to the genus Brumptomyia. Lutzomyia longipalpis, a proven vector of AVL, was the predominant species (71.85%) throughout the time period. The interference of climatic factors (temperature, humidity, and rainfall) over the populational dynamics of the sand flies was determined. Statistical analysis of the data showed a significant correlation among the number of phlebotomine sand flies collected, rainfall, and humidity, whereas the effect of temperature was negligible, in that particular region. The amount of collected phlebotomine, the number of human cases, and the prevalence of canine AVL in the districts of Porteirinha are discussed

Phlebotomine sand flies (Diptera: Psychodidae) in the municipality of Várzea Grande: an area of transmission of visceral leishmaniasis in the state of Mato Grosso, Brazil

“…The predominance of L. longipalpis found in the present study showed to be in accordance with Missawa and Lima (2005) in the same municipality and other localities as reported by Oliveira et al (2003Oliveira et al ( , 2006 for Campo Grande, MS, Resende et al (2006) and Souza et al (2004) for Belo Horizonte, state of Minas Gerais (MG), Barata et al (2004Barata et al ( , 2005, and França- for Porteirinha, MG, Monteiro et al (2005) for Montes Claros, MG.…”

“…The closeness between the houses and the domestic animal shelters may account for the presence of insects indoors together with their capacity of endophilia. The high frequency of male insects found in both intra-and peridomiciliary areas has corroborated data provided by Oliveira et al (2003Oliveira et al ( , 2006, Resende et al (2006), Barata et al (2004Barata et al ( , 2005, evidencing the high adaptation capacity of sand flies enabling the disease transmission. The process of urbanization of insects and, consequently, of the disease is correlated with disorganized urban growth, followed by human migration from rural to urban regions and the environmental destruction.…”

“…The non-significant correlation between insect density and the bioclimatic variables under study had also not been observed by Souza et al (2004) in Belo Horizonte, and Rebêlo (2001) in São Luis, state of Maranhão. The non-significant effect of temperature on phlebotomine density was reported by Barata et al (2004), although Monteiro et al (2005) have found correlations between high temperatures and peaks of VL transmission. França-Silva et al (2005) showed no correlation between vector density and the climatic variables, temperature and ARH.…”

“…Correspondence between human VL cases and high phlebotomine density was not observed between 2004 and 2006 in VG, although Barata et al (2004) and Souza et al (2004) have measured correlations between phlebotomine density, prevalence of VL human cases and presence of domestic animals in Porteirinha and Belo Horizonte, MG. Monteiro et al (2005) and França- have correlated the presence of high vector density and high VL canine prevalence in Montes Claros and Porteirinha, MG.…”

“…França-Silva et al (2005) showed no correlation between vector density and the climatic variables, temperature and ARH. On the other hand, Resende et al (2006) reported an increased number of phlebotomine sand flies, mainly L. longipalpis, when the combination of high temperature averages and regular rain periods occurred, as well as Monteiro et al (2005), Barata et al (2004) and Oliveira et al (2003), who have associated phlebotomine density with the first rainy periods and high ARH.…”