From January 1989 to April 1995, 465 specimens of Triatoma vitticeps
were collected in the locality of Triunfo, 2nd District of Santa Maria Madalena municipal district,
State of Rio de Janeiro. The bugs were found indoors by local residents with predominance
of adults. The flight activity was high in hot months when the incidence in the domicile also
increased. Two hundred and two bugs (111 alive and 91 dead) were examined for
Trypanosoma cruzi infection. This was detected in 31 of the dead bugs (34%) and 88
(79%) of the live bugs examined. With a view to investigate the possible vertebrate hosts of
the T. cruzi isolates, the blood of 122 mammals was examined through
Giemsa-stained smears, hemocultures and xenodiagnosis. T. cruzi was detected in three specimens
of Didelphis marsupialis and T. (M.) theileri was detected in one specimen
of Bos taurus. The parasites were isolated from triatomine feces, xenoculture and
hemoculture. No evidence of human infection was detected in 58 inhabitants examined, as
evaluated by indirect imunofluorescence technique using T. cruzi epimastigotes as
antigens. These results show that T. vitticeps is still a sylvatic species although
nymphs have been found inside the domicile. Thus, an epidemiological vigilance is necessary to
know the behaviour of this species following the continuous modifications promoted by the
presence of man.
