SYLVATIC TRIATOMINES (HEMIPTERA, REDUVIIDAE) IN BOLIVIA - TRENDS TOWARD DOMESTICITY AND POSSIBLE INFECTION WITH TRYPANOSOMA-CRUZI (KINETOPLASTIDA, TRYPANOSOMATIDAE)
F. Noireau et al., SYLVATIC TRIATOMINES (HEMIPTERA, REDUVIIDAE) IN BOLIVIA - TRENDS TOWARD DOMESTICITY AND POSSIBLE INFECTION WITH TRYPANOSOMA-CRUZI (KINETOPLASTIDA, TRYPANOSOMATIDAE), Journal of medical entomology, 32(5), 1995, pp. 594-598
The risk of domestic transmission of Trypanosoma cruzi (Chagas) by syl
vatic triatomines was assessed in an isolated area of the subandean re
gion of Bolivia. None of the 390 residents examined had serological ev
idence of infection. Two sylvatic triatomine species, Eratyrus mucrona
tus (Stal) and Triatoma sordida (Stal), were found in houses and in pe
ridomestic structures. The collection of nymphal instars of both speci
es from some houses indicated possible domesticity. Microscopic examin
ation of feces from 92 insects showed no parasites, and cultures from
the guts of 30 insects were negative. Nevertheless, a polymerase chain
reaction (PCR) test performed on the same fecal samples showed the pr
esence of T. cruzi DNA in 19.1 and 12.5% of E. mucronatus and T. sordi
da, respectively. These 16 PCR-positive samples were hybridized with 2
T. cruzi-specific probes known from the domestic cycle in Bolivia (cl
ones 20 and 39). At least 1 of these clones was identified in 7 bugs (
5 E. mucronatus and 2 T. sordida). Moreover, no hybridization was obse
rved with these probes in 8 E. mucronatus and 1 T. sordida samples tha
t showed an amplified band by PCR. These data indicated that T. cruzi
clones, genetically unrelated to clones 20 and 30, also were circulati
ng in this area. Based on these results, the 2 sylvatic triatomine spe
cies encountered in Apolo should not be overlooked as possible local v
ectors of T. cruzi.