A second generation assay for antibody to hepatitis C virus (anti-HCV) was used to screen 78 southern Indian individuals with a high risk of infection. RT-PCR targeted at the 5' end untranslated region (5'UTR) of the HCV genome was used to evaluate evidence of viraemia in 32 anti-HCV positive sera. The PCR products amplified from the 5'UTR of the HCV genome from 24 patients were sequenced, revealing the existence of two distinct groups of sequences: 21 corresponded to HCV type 1 while the other three sequences had 95 % to 99 % identity to HCV type 3. Two of these three isolates had more than 90 % nucleotide identity in the NS5 region to established 3b sequences whereas the other had less than 74 % nucleotide identity to any of the published genotype 3 (3a, 3b, 3c, 3d, 3e and 3f) sequences. However, a search of the EMBL nucleotide database revealed 91% identity to the unpublished sequence of an isolate of HCV from Indonesia. We provide evidence that these two isolates may represent a novel subtype within genotype 3. Our data also suggest that HCV genotype 1 predominates over HCV genotype 3 in southern India.
Ten hepatitis B surface antigen seropositive carriers (5 asymptomatic and 5 with chronic liver disease) were tested for HBeAg/anti-HBe and for HBV-DNA using the polymerase chain reaction. Five were DNA-positive, 2 with HBeAg and 3 with anti-HBe. Nucleotide sequences were determined for these 5 cases. Hepatitis B virus DNA from one cirrhotic carrier with anti-HBe had a mutation in the precore region (nucleotide position 1862) which may affect signal peptide cleavage and HBeAg synthesis. In the other 2 anti-HBe- and DNA-positive cases, a cirrhotic carrier and an asymptomatic case, there was a mutation at nucleotide position 1896 leading to a termination codon in the precore region. In all 5 patients, except for one or two missense mutations, there was no significant variation in the core region.
Hepatitis B virus (HBV) infections are occasionally associated with unusual serological profiles which may be attributed to the lack of immune responsiveness of the patients or to variants of the virus. The term HBV2 was introduced to describe potential variants of HBV which do not elicit a detectable immune response to the nucleocapsid (anti-HBc) in apparently immune-competent patients. The entire nucleotide sequences of the nucleocapsid genes of viruses from two Spanish patients with HBV2-like infections are reported here. In-frame deletions and other mutations in these sequences may account, at least in part, for the unusual serological profiles of the patients. Antibody responses to viral proteins containing deletions may not be detected by commercially available assays.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.