RESUMEN
Nine species of sandflies, Lutzomyia (Nyssomyia) whitmani (Antunes and Countinho), Lutzomyia (Nyssomyia) intermedia (Lutz and Neiva), Lutzomyia (Psathyromyia) shannoni (Dyar), Lutzomyia migonei (Franca), Lutzomyia (Pintomyia) fischeri (Pinto), Lutzomyia (Pintomyia) pessoai (Countinho and Barretto), Lutzomyia cortelezzii (Brethes), Lutzomyia walkeri (Newstead) and Lutzomyia (Trichopygomyia) longispinus (Mangabeira), were caught, by human bait and Shannon trap, in four areas of Paraguay hyper-endemic for human leishmaniasis. Lutzomyia whitmani and L. intermedia were the predominant species. All the species collected were found to be anthropophilic. Hindgut infections with leishmanial promastigotes were observed in only one (0.38%) of the 266 L. whitmani dissected. No L. intermedia were found infected, giving an overall infection rate of one (0.16%) of 615 flies dissected. The results indicate a very low rate of natural infection in endemic areas of Paraguay.
Asunto(s)
Insectos Vectores/parasitología , Leishmania/aislamiento & purificación , Leishmaniasis/transmisión , Psychodidae/parasitología , Animales , Humanos , Insectos Vectores/clasificación , Paraguay , Psychodidae/clasificaciónRESUMEN
Sera from 38 Paraguayans with positive skin tests to Leishmania braziliensis panamensis and 51 sera from Paraguayan patients in different stages of Chagas' disease were analyzed by Western blotting using antigen from Trypanosoma cruzi Y strain epimastigotes and from L. b. panamensis promastigotes. Using a single serum sample, distinctive patterns of IgG antibody response to both antigens were identified allowing the differentiation between T. cruzi infection, Leishmania infection, and probable double infection. Sera from patients with T. cruzi infections consistently recognized bands of approximately 25 kDa, 38 kDa, and greater than 97 kDa in T. cruzi antigen lysates and recognized a band of 38 kDa of 66 kDa in Leishmania antigen lysates but did not consistently recognize any bands using T. cruzi antigen. Sera from patients with probable double infections recognized all bands normally detected by individual sera from patients infected with either T. cruzi or Leishmania. In our study population, T. cruzi infection among leishmaniasis patients was as frequent as among individuals free of leishmaniasis.