ABSTRACT
Human cases of American cutaneous leishmaniasis (ACL) have been recorded in Serra da Cantareira, in the Greater São Paulo Metropolitan Region, where two conservation units are situated, the Parque Estadual da Cantareira and the Parque Estadual Alberto Löfgren. The present study aimed to identify the sandfly fauna and some of its ecological aspects in these two parks and their surrounding area to investigate Leishmania sp. vectors. The captures were undertaken monthly from January to December 2009, from 6:00 p.m. to 6:00 a.m., with automatic light traps installed in forests and peridomicile areas and with modified black/white Shannon traps in the peridomicile. A total of 12 species and 5,436 sandflies were captured: with automatic light traps (141), Shannon traps (5,219) and attempting to bite the researchers while they were conducting the collection in Shannon traps (76). Pintomyia fischeri and Migonemyia migonei were the most abundant species. Pi. fischeri predominated in all three kinds of captures (49%, 88.8% and 65.8%, respectively). Mg. migonei was the second most prevalent in Shannon traps (10.0%) and attempting to bite the researchers (22.4%). Pi. fischeri females were significantly more attracted to black and those of Mg. migonei to white Shannon traps. A positive and significant correlation was observed between the numbers of Pi. fischeri and the mean of minimum relative humidity values on the fifteen days prior to capture, while there was a negative and significant correlation between the relative humidity on the capture day and the two most abundant species. The anthropophilia and high frequencies of Pi. fischeri and Mg. migonei suggest that both species may be transmitting ACL agents in this region.
Casos humanos de leishmaniose tegumentar americana (LTA) têm sido registrados na Serra da Cantareira, região da Grande São Paulo, onde se situam o Parque Estadual da Cantareira e o Parque Estadual Alberto Löfgren. O estudo teve como objetivo identificar a fauna flebotomínea e alguns de seus aspectos ecológicos nos dois parques e área adjacente, para investigar vetores de Leishmania sp. As capturas ocorreram de janeiro a dezembro de 2009, das 18 às 06 horas, com armadilhas automáticas luminosas instaladas em matas e peridomicílios, e com armadilhas de Shannon modificadas, nas cores branca e preta, em peridomicílio. Foram capturadas 12 espécies e 5.436 flebotomíneos por armadilhas automáticas luminosas (141), armadilhas de Shannon (5.219) e tentando picar os pesquisadores enquanto coletavam na armadilha de Shannon (76). Pintomyia fischeri e Migonemyia migonei foram as mais abundantes. Pi. fischeri predominou nos três métodos de coleta com 49,0%, 88,8% e 65,8%, respectivamente, e Mg. migonei foi a segunda mais prevalente na Shannon (10,0%) e tentando picar os pesquisadores (22,4%). Fêmeas de Pi. fischeri foram significativamente mais atraídas à Shannon preta e Mg. migonei à branca. Houve correlação positiva e significante entre o número de Pi. fischeri e a média das mínimas da umidade relativa nos 15 dias anteriores ao dia da coleta, e negativa e significante para as duas espécies mais abundantes em relação a umidade relativa no dia da coleta. Altas frequências e antropofilia de Pi. fischeri e de Mg. migonei sugerem que ambas podem estar atuando na transmissão da LTA na área.
Subject(s)
Animals , Female , Humans , Male , Psychodidae , Brazil , Ecosystem , Population DensityABSTRACT
The dispersal and survival of the phlebotomines Nyssomyia intermedia and Nyssomyia neivai (both implicated as vectors of the cutaneous leishmaniasis agent) in an endemic area was investigated using a capture-mark-release technique in five experiments from August-December 2003 in municipality of Iporanga, state of São Paulo, Brazil. A total of 1,749 males and 1,262 females of Ny. intermedia and 915 males and 411 females of Ny. neivai were marked and released during the five experiments. Recapture attempts were made using automatic light traps, aspiration in natural resting places and domestic animal shelters and Shannon traps. A total of 153 specimens (3.48 percent) were recaptured: 2.59 percent (78/3,011) for Ny. intermedia and 5.35 percent (71/1,326) for Ny. neivai. Both species were recaptured up to 144 h post-release, with the larger part of them recaptured within 48 h. The median dispersion distances for Ny. intermedia and Ny. neivai, respectively, were 109 m and 100 m. The greatest dispersal range of Ny. intermedia was 180 m, while for Ny. neivai one female was recaptured in a pasture at 250 m and another in a pigsty at 520 m, showing a tendency to disperse to more open areas. The daily survival rates calculated based on regressions of the numbers of marked insects recaptured on the six successive days after release were 0.746 for males and 0.575 for females of Ny. intermedia and 0.649 for both sexes of Ny. neivai. The size of the populations in the five months ranged from 8,332-725,085 for Ny. intermedia males, 2,193-104,490 for Ny. intermedia females, 1,687-350,122 for Ny. neivai males and 254-49,705 for Ny. neivai females.