Natural infection of phlebotomines (Diptera: Psychodidae) in a visceral-leishmaniasis focus in Mato Grosso do Sul, Brazil

Abstract

SUMMARYThe main purpose of this study was to investigate natural infection by Leishmania in phlebotomine females in a visceralleishmaniasis focus in Antonio João county in Mato Grosso do Sul State, Brazil. Between June and October 2003, the digestive tracts of 81 females captured in Aldeia Campestre, Aldeia Marangatu and Povoado Campestre were dissected. The females were separated by species, location, area and date of capture into 13 groups and kept in ethanol 70%. To identify the Leishmania species using the PCR technique, amplifications of the ribosomal-DNA (rDNA) and mini-exon genes were analyzed. Of the 81 specimens, 77 (95%) were Lutzomyia longipalpis, making this the most common species; only one specimen of each of the species Brumptomyia avellari, Evandromyia cortelezzii, Evandromyia lenti and Nyssomyia whitmani was found. Trypanosomatids were identified in eight of the nine groups of Lutzomyia longipalpis (10.39%) one group from Aldeia Campestre, one from Aldeia Marangatu and six from Povoado Campestre; of the eight groups, one from Aldeia Marangatu and another, with promastigotes forms also confirmed by dissection (1.23%) from Povoado Campestre, were identified by PCR as Leishmania chagasi (2.6%). The other groups gave negative results. These findings indicate that there is a high risk of leishmaniasis transmission in this area.

Distribution of phlebotomine fauna (Diptera: Psychodidae) across an urban-rural gradient in an area of endemic visceral leishmaniasis in northern Brazil

“…Several studies have reported that the natural infection rate is low among sandflies and is approximately 1%. Nascimento et al (2007) dissected 81 females and detected only one infected fly. Neitzke et al (2008) analysed 2,487 females and found an infection rate of 0.04%.…”

Flebotomíneos (Diptera: Psychodidae: Phlebotominae) no Município de Três Lagoas, área de transmissão intensa de leishmaniose visceral, Estado de Mato Grosso do Sul, Brasil

“…cruzi como a espécie mais abundante nessas áreas, dentre os possíveis vetores de leishmaniose visceral. Tais fatos poderiam ser explicados por diferenças na cobertura vegetal, condições climáticas e pelo grau de alterações a m b i e n t a i s a n t r ó p i c a s e s p e c í f i c a s d e c a d a 13,26,14,42,15,16,17 localidade .…”

“…fue igual a 1,18%; ese valor, aunque bajo, está en acuerdo a los estudios nacionales e internacionales que encontraron 42,15,50,5 tasas entre 1% y 2%…”

Frequency and diversity of phlebotomine sand flies (Diptera: Psychodidae) in Sinop, State of Mato Grosso, Brazil

“…However, neighborhoods remain close to forest areas and, consequently, there is more contact between wildlife, domestic animals, and humans. Domestic animals may become a new, easy, and relatively safe food source for sandflies, providing ideal conditions for them to adapt to urban areas (33) (34) .…”