Análise da fonte alimentar de Panstrongylus megistus (Hemiptera, Reduviidae, Triatominae) e sua atual importância como vetor do Trypanosoma cruzi, no Estado de Minas Gerais

Abstract

INTRODUÇÃO: A pesquisa da fonte alimentar dos triatomíneos auxilia no conhecimento sobre a biologia destes insetos, inclusive para inferir-se a importância dos mesmos como transmissores do Trypanosoma cruzi ao homem. MÉTODOS: O presente estudo objetivou registrar, através da reação de precipitina, a fonte alimentar de triatomíneos provenientes de 54 municípios da região centro-oeste de Minas Gerais, assim como a infecção natural destes para flagelados semelhantes ao Trypanosoma cruzi. RESULTADOS: De julho de 2003 até março de 2007, foram avaliados 416 insetos, todos da espécie Panstrongylus megistus. Somando-se as ocorrências, as aves (70%) e os humanos (22,5%) constituíram as principais fontes sanguíneas. Encontrou-se 16 (3,8%) insetos positivos para flagelados semelhantes ao Trypanosoma cruzi sendo que oito realizaram hematofagia no homem. CONCLUSÕES: Os resultados demonstram necessidade de acentuar a vigilância entomológica na região, visto que foi detectada a possibilidade de ocorrência de novos casos da doença de Chagas através da transmissão vetorial.

Occurrence and distribution of triatomines (Hemiptera: Reduviidae) in municipalities of the Northeastern region of Minas Gerais State, Brazil

“…Adults seem to disperse from there by fl ight during the warmest and most humid periods of the year, as observed in municipalities of the midwestern part of Minas Gerais ( Figure 2D) (9) . In that region, 22.5% of 416 P. megistus specimens had ingested human blood and 3.8% of specimens were positive for trypanosomatids, thus surpassing the percentage reported herein (2.7%) (10) .…”

Triatomines in dwellings and outbuildings in an endemic area of Chagas disease in northeastern Brazil

“…This is due primarily to the transmission of Trypanosoma cruzi by Triatoma infestans, which also lives in human dwellings 29 . Thus, dogs and cats play an important role in the maintenance of the disease, in addition to other domestic and wild mammals that frequent the areas surrounding homes 3,4,12 . In the case of cats, although infection rates are low, their association with the domestic cycle is closely associated with their wandering habits 30 .…”

“…Triatomines undergo a domiciliation process when they are forced out of their wild environments due to habitat destruction around dwellings, after which they find shelter in rural constructions [6][7][8] . In addition, the presence of domestic animals and peri-domestic constructions used for animal maintenance and breeding greatly influences the presence and transmission of parasites because they provide a permanent food source and promote contact between vectors and humans 7,[9][10][11][12] .…”

Evaluation of natural foci of Panstrongylus megistus in a forest fragment in Porto Alegre, State of Rio Grande do Sul, Brazil

“…B irds, although refractory to parasites, enable the maintenance of colonies and can act as population growth vectors, thereby increasing the risk of disease transmission, especially if the triatomines had previous contact with an infected mammal 61 . In an analysis of populations in the State of Minas Gerais Midwest, Villela et al 62 also found a higher level of blood feeding on birds in triatomines captured in peridomiciliary environments; however, the majority (90.4%) of individual triatomines fed on only one source (bird and others species). The same authors showed that 44% of infected bugs had this source.…”