[Triatomids and forest reservoirs of Trypanosoma cruzi in the state of Paraná, southern Brazil. Preliminary results]. / Estudo sobre triatomíneos e reservatórios silvestres de Trypanosoma cruzi no Estado do Paraná, Sul do Brasil. Resultados preliminares.

In the rural area of five municipalities of the Northeast of the State of Paraná, Brazil, 154 adults or nymphs of Triatoma sordida and 2 Panstrongylus megistus were captured in 21 (41.2%) of 51 dwellings at the peridomestic sites. Trypanosoma cruzi-like organisms were found in 58 out of the 135 (43.0%) triatomids. Moreover, it was also found in the blood of 4/7 opossum (Didelphis sp). The triatomine infestation was more prevalent in the peridomicile than inside house. The forsaken wooden house presented the highest level of infestation (53.8%). Although the rural area of the Northeast of the State of Paraná is considered under epidemiologic surveillance it still presents a high level of peridomestic infestation by triatomids highly infected with T. cruzi-like organisms.

Trypanosoma cruzi: chemotherapy with benznidazole in mice inoculated with strains from Paraná state and from different endemic areas of Brazil.

Strains of Trypanosoma cruzi from different geographical areas have shown different levels of susceptibility to trypanosomicidal drugs. The susceptibility in vivo to benznidazole was investigated in eighteen strains of T. cruzi. Twelve were isolated from chronic chagasic patients from different Chagas' disease endemic areas. The other six strains were isolated from the northwestern region of Paraná state; two of them from patients, three from triatomines (Triatoma sordida) and one from wild reservoir (Didelphis sp.). To test drug the infected mice were divided into two groups of twenty. One group was treated with benznidazole for twenty consecutive days and the other group was used as untreated control. The treatment began after detection of the infection by direct blood examination or haemoculture. The control of cure was done through haemoculture and indirect immunofluorescence test. The drug eliminated the inflammatory lesions of the skeletal muscle of mice considered cured and from the heart of most of them. Moreover, the inflammatory lesions were reduced in treated but not cured animals. The T. cruzi strains studied showed a gradient of drug susceptibility that varied from 0% to 100%. Ten strains were considered sensitive to the treatment (61 to 100% of cure), one strain was partially sensitive (50% of cure) and seven strains were considered resistant to the treatment (0 to 40% of cure). This variation was observed both in strains of T. cruzi isolated from domestic and sylvatic cycles.