ABSTRACT
In paralel with several other epidemiologic and entomologic data of 19 Municipalities of Espírito Santo State, Brazil, the feeding pattern of 222 Triatoma vitticeps is studied through precipitin tests. Very high levels of natural infection with Trypanosoma cruzi are observed in adult insects, in contrast with the abscence or minimum degrees of infection among nymphs and human individuals. The precipitin tests showed the contact of the insects with multiple blood sources, chiefly human and birds, followed by rodents and marsupials. The data suggest that T. vitticeps in spite of being highly antropophilic, become infected by T. cruzi in sylvatic ambient and occasionally invade houses. The species doesn't seem to be - at least until now - a good vector in the domestic cycle of Chagas' disease. Several factors seem to be involved in this conclusion, mainly the low density of the insect in the houses, its hardness to coloniza them, its slowness concerning to suction and defecation and possibly its low susceptibility to different T. cruzi strains.
Subject(s)
Humans , Animals , Triatoma/parasitology , Chagas Cardiomyopathy/pathology , Chagas Disease/parasitology , Reduviidae , HemipteraABSTRACT
Foram realizados experimentos em laboratório com o Astronotus ocellatus, predador de Biomphalaria glabrata, objetivando determinar a influência do peixe sobre o ritmo de desovas do molusco hospedeiro da esquistossomose, ademais de sua eficácia predatória, tanto em relaçäo a B. glabrata, quanto a peixes do gênero Poecilia. Constatou-se que A. ocellatus parece näo predar as cápsulas oviferas do caramujo, mas apenas o molusco. Também verificou-se que a predaçäo foi estatisticamente mais significativa para B. glabrata do que para Poecilia. Os resultados desse experimento sugerem que a maior predaçäo dos caramujos decorreu do fato de se constituirem presas mais fáceis que os peixes do gênero Poecilia