Diversity of Hepatitis C virus in Southern India Based on 5′UTR Sequence

Abstract

Hepatitis C virus (HCV) exhibits genotypespecific variations in geographical distribution as a consequence of drug and immune induced evolution. Present study was aimed at discerning the distribution and prevalence of the various genotypes and subtypes of HCV in southern India. The HCV positive patient's serum was collected from different hospitals and blood banks from the states of Kerala, Tamil Nadu, Andhra Pradesh and Karnataka. Among 114 HCV positive samples, we could find only 44 isolates that are found both positive in ELISA and RT-PCR. From these samples 5 0 untranslated region (5 0 UTR) were amplified, sequenced and sub typed. Analysis of 5 0 UTR region of the 44 isolates shows that, genotypes 1, 3, 4 and 6 are present with genotype 3 being the most frequent. The present study shows that HCV genotype 3 subtype B was the most prevalent, forming 47.7 % among the population in southern India. The present study urges for discovering novel therapeutic agents that should be specific to genotype 3 subtype B, for the management of HCV in southern India.Hepatitis C virus (HCV, genus: Hepacivirus, family: Flaviviridae) exists as six major genotypes and more than 60 defined subtypes. The genomic sequences of different HCV genotypes vary by 30-35 % between genotypes and by 20-25 % between subtypes [19]. Such genetic heterogeneity accounts for several of the differences observed in the prognosis of the disease, as well as in the differences seen in response to prophylactic treatment procedures. For example, in individuals infected with HCV genotype 1, complete and permanent clearance of the infection has been observed in only 10-20 % of those on monotherapy with interferon and 40-50 % in those on combination therapy with interferon and ribavirin. The disease tends to be chronic in the rest, ultimately ending in hepatocellular carcinoma. However, in the case of type 2 and 3, 50 % on mono-therapy and 70-80 % on combination therapy show sustained clearance of the virus [15,26