We experienced six cases of hepatitis E within 18 months around Gifu city. The phylogenetic analysis indicated that the 6 hepatitis E virus (HEV) strains were included in different lineages, respectively. One case showed marked symptoms of hepatitis and was infected with a genotype 4 Aichi/Shizuoka strain which is ordinary isolated from wild animal. The case had history of consuming raw pig liver. The fact may indicate that Aichi/Shizuoka strains are confined not only to wild animal but also to pig bred around Gifu city. Other 5 cases had no clear risk factor of acquiring HEV and did not show obvious symptoms of hepatitis. HEV infection may occur more commonly than we think by various HEV lineages from unknown reservoirs.
Saga prefecture has been reported to be the most prevalence area of hepatitis C virus (HCV) infection in Japan. We investigated the results of medical screening for anti-HCV and HCV-RNA on the island of Saga. Anti-HCV testing was performed on 289 individuals, and the results showed that 22 were positive for anti-HCV, and 11 were positive for HCV-RNA. A blood transfusion history was a significant predictor of anti-HCV positive status, while no such relationship was found for HCV-RNA positivity. The HCV-RNA spontaneous loss rate was 45%. The vertical transmission from pregnant females to the infants may have led to the highest of anti-HCV positive ratio and the HCV-RNA disappearance ratio.
Amino acid (aa) substitution at position 93 of the HCV NS5A region predicts the effectiveness of combination therapy with the protease inhibitor and NS5A inhibitor. The qualitative analysis assay and the comparative quantitative analysis assay based on the PCR-Invader technology, were developed to detect drug-resistance substitution at aa93 with high levels of sensitivity. In the mixtures of plasmids containing wild-type and drug-resistance substitution, both assays were able to be distinguished up to a mixed population containing 1%drug-resistance substitution. Clinical samples at the baseline of HCV therapy were examined by the PCR-Invader assays and direct sequencing. The PCR-Invader assays found drug-resistance substitutions that were detected by direct sequencing. Furthermore, they illustrated the presence of drug-resistance substitution that direct sequencing couldn't discover. The PCR-Invader assays were useful in detecting drug-resistance substitution at aa93 of the HCV NS5A region.