Prevalence of hepatitis C virus (HCV) infection and HCV genotypes of hemodialysis patients in Salvador, Northeastern Brazil

Hepatitis C virus (HCV) infection has been identified as the major cause of chronic liver disease among patients on chronic hemodialysis (HD), despite the important reduction in risks obtained by testing candidate blood donors for anti-HCV antibodies and the use of recombinant erythropoietin to treat anemia. A cross-sectional study was performed to estimate the prevalence of HCV infection and genotypes among HD patients in Salvador, Northeastern Brazil. Anti-HCV seroprevalence was determined by ELISA in 1243 HD patients from all ten different dialysis centers of the city. HCV infection was confirmed by RT-PCR and genotyping was performed by restriction fragment length polymorphism. Anti-HCV seroprevalence among HD patients was 10.5 percent (95 percent CI: 8.8-12.3) (Murex anti-HCV, Abbott Murex, Chicago, IL, USA). Blood samples for qualitative HCV detection and genotyping were collected from 125/130 seropositive HD patients (96.2 percent). HCV-RNA was detected in 92/125 (73.6 percent) of the anti-HCV-positive patients. HCV genotype 1 (77.9 percent) was the most prevalent, followed by genotype 3 (10.5 percent) and genotype 2 (4.6 percent). Mixed infections of genotypes 1 and 3 were found in 7.0 percent of the total number of patients. The present results indicate a significant decrease in anti-HCV prevalence from 23.8 percent detected in a study carried out in 1994 to 10.5 percent in the present study. The HCV genotype distribution was closely similar to that observed in other hemodialysis populations in Brazil, in local candidate blood donors and in other groups at risk of transfusion-transmitted infection.

Screening the mutagenic activities of commonly used antiparasite drugs by the simultest, a simplified Salmonella/microsome plate incorporation assay

As atividades mutagenicas de 16 drogas com acao anti-parasitaria foram avaliadas pelo Simultest em ensaios qualitativos (spot testes) e quantitativos (incorporacao em placa) com uma mistura das linhagens indicadoras de Salmonella typhimurium TA97, TA98, TA100 e TA102. Quatro drogas anti-doenca de Chagas (nifurtimox, benzonidazol, CL 64,855 e MK 436) e duas drogas anti-amebiase (metronidazol e tinidazol) deram resultados positivos em testes qualitativos e a incorporacao de fracao microssomal de figado de rato nao alterou os resultados. Curvas comparadas de efeito da dose da atividade mutagenica do metronidazol, benzonidazol e CL 64,855 detectadas oelo Simultest e linhagens indicadoras individuais demonstraram que as duas abordagens possuem sensibilidades semelhantes. Os resultados corroboram a validade do Simultest como uma versao simplificada, rapida e economica do teste de Ames no rastreamento preliminar de drogas potencialmente mutagenicas

Evaluation of genotoxic activity in the blood and urine of guinea pigs treated with nifurtimox and benznidazole

1. The mutagenicity of serum and urine from fuinea pigs treated with a single oral dose (500 mg/Kg) of benznidazole and nifurtimox was assayed using the Salmonella/plate incorporation test with strain TA100 and a nitroreductase-deficient derivative, TA100NR. 2. The urine and blood of animals treated with nifurtimox were not mutagenic for either tester strain. 3. The urine and blood of animals receiving benznidazole were mutagenic to the TA100 but not to the TA100NR strain. Similar results were obtained with nitrofurantoin-treated animals. Maximum mutagenicity values were obtained in serum and urine of treated animals 90 min and 24 h after administration, respectively. 4. Mutagenicity induced by benznidazole in the serum and urine of treated animals was not altered when assayed in anaerobic environments. 5. These results indicate that benznidazole and nifurtimox are not metabolized by the mammalian host into stable mutagenic derivatives detectable by the Ames test. Based on these data, we suggest that the potential cancer risk to patients treated with these drugs is small but should be further evaluated