Phlebotomine sandflies ( Diptera : Psychodidae ) in Governador Valadares , a transmission area for American tegumentary leishmaniasis in State of Minas Gerais , Brazil Flebotomíneos ( Diptera : Psychodidae ) em Governador Valadares , área de transmissão de leishmaniose tegumentar americana , no Esta

Introduction: A study on the phlebotomine sandfly fauna was carried out in an endemic area for American tegumentary leishmaniasis in the municipality of Governador Valadares, in the State of Minas Gerais, Brazil. Methods: Captures were undertaken using HP light traps in four districts, on three nights per month, for one year (from January to December 2008). Correlations between climatic factors (temperature, relative air humidity and rainfall) and the numbers of sandflies collected was observed. Results: 5,413 phlebotomine specimens were caught and were identified as belonging to 12 species. Of these specimens, 2,851 (52%) were females and 2,562 (48%) were males. Conclusions: Lutzomyia intermedia predominated (29.9% of the species caught), thus suggesting that they were responsible for transmission of American tegumentary leishmaniasis, together with L. whitmani, which was also found in the area (4.3%). The presence of L. longipalpis (11.9%), the main vector for visceral leishmaniasis in Brazil, is an important finding, which makes rigorous entomological surveillance of the area necessary.

In Brazil, American tegumentary leishmaniasis (ATL) is an important public health problem because of increasing numbers of human cases.The infection can cause mutilating lesions and lead to loss of the capacity to work and even death 1 .Over recent years, the significant increase in deforestation has favored adaptation of vectors to anthropic environments and consequently increased human exposure to the parasite 2 .The circulation of Leishmania in domestic environments has favored the emergence of a distinct profile for transmission of the disease that differs from the classical pattern 3 and is associated with a wider range of activities.
Nowadays, in the State of Minas Gerais (MG), ATL is present in practically all municipalities, in areas where highways and hydroelectric power stations have been built and where clusters of people have settled 4 .In addition to its continuing presence in old endemic foci in the Atlantic forest and in the Rio Doce and Mucuri valleys 5 , numerous cases have also been reported in urban areas of large and medium-sized cities, such as Belo Horizonte, Montes Claros and Governador Valadares.
Governador Valadares, in MG, is considered to be an endemic area.It had 221 new cases of ATL between 2004 and 2007, and approximately 75% of the cases were in the urban area.In an epidemiological study in the 1970s, in the municipality of Caratinga, near to Governador Valadares, Mayrink et al 5 recorded the presence of Lutzomyia whitmani and L. intermedia, which are known to transmit Leishmania braziliensis in southeastern Brazil 6 .
The aim of the present study was to identify the phlebotomine fauna and some aspects of the population's behavior, such as the frequency of presence in peridomestic and domestic environments, seasonal variation of the species implicated as vectors Article/Artigo DOI: 10.1590/S0037-86822011005000003

Barata RA et al -Phlebotomines in Governador Valadares
for leishmaniasis and the influence of climatic factors on the species density.Through this, better understanding of the transmission cycle of ATL in the municipality was sought, along with correlations between the data obtained and the risk of Leishmania transmission, as support for applying control actions in the area.

Study area
The municipality of Governador Valadares (18° 51' 12'' S and 41° 56' 42'' W) is part of the administrative area of Rio Doce valley.The total area of the municipality is 2,349 km 2 , and it is physically characterized by predominance of hills, with altitude levels ranging from 191 to 1,008 m above sea level.The climate is classified, according to Koppen, as the AW type (tropical sub-warm and subdry), with a mean annual temperature of 25.6 °C and mean annual rainfall of around 1,350 mm.
Capture sites Systematic captures were carried out using HP light traps 7 between January and December 2008.Sixteen traps were distributed in four districts of the municipality (Elvamar, Vila Isa, Vila Parque Ibituruna and Village da Serra): two inside homes (domestic areas) and two in areas surrounding homes (peridomestic areas).These districts are characterized as transitional environments between the urban area and an area of environmental preservation.These traps were exposed from 4:00 pm to 8:00 am, for three consecutive nights every month, always in the last week of each month.

Phlebotomine identification
The taxonomic keys of Young and Duncan 8 and Forattini 9 were used for identification of the sandfly species.Specimens with missing or damaged characteristics that impaired identification at the species level were considered to be Lutzomyia spp.Females belonging to the genus Brumptomyia were not identified to the species level.

Climatic data
Climatic data for the study period were obtained through the website http://www.inmet.gov.br/sim/sonabra/convencionais.php.Average monthly values were used in our study.

Statistical analysis
The correlations between climatic variables (temperature, air humidity and rainfall) and population density of phlebotomines were evaluated by means of Spearman's coefficient (p-value ≤ 0.05).A total of 5,413 specimens was caught, of which 2,851 were females (52%) and 2,562 were males (48%).The peridomestic and domestic areas accounted for 64% and 36% of the specimens caught, respectively.Lutzomyia intermedia was the predominant species, comprising 29.9% of the total number of phlebotomines collected (Table 1).The monthly averages for climatic variables, considering rainfall, temperature and relative air humidity, can be seen in Table 2.The correlation between the number of phlebotomines captured and the climatic conditions is represented in Figure 1.All the variables evaluated showed a positive Spearman correlation coefficient in relation to phlebotomine density, but only the rainfall and humidity showed significant values (p = 0.008 and p = 0.007, respectively), while the temperature variable showed a p-value = 0.064.

The phlebotomine fauna of Governador
Figure 2 shows the monthly distribution of vector species in the municipality of Governador Valadares.Table 3 displays the monthly distribution of phlebotomines captured in each neighborhood, in Governador Valadares, from January to December, 2008.It was observed that in all neighborhoods located in the transitional area between the sylvatic and urban environments, the number of insects captured was considerable, with greatest success in Village da Serra and Vila Isa, probably due to the presence of domestic animals (dogs, chickens, cows, horses and pigs) next to the sampling sites.