Genotyping of Hepatitis C virus (HCV) in infected patients from South India.

Hepatitis C virus shows substantial nucleotide sequence diversity distributed throughout the viral genome. In the present study genotyping for Hepatitis C virus (HCV) infected patients was based on RFLP analysis of 5' UTR and using type specific primers of NS5B regions. It was observed that 60% of the patients (30 patients with chronic hepatitis) were infected with variants of genotype 1 and 40% of the patients (4 chronic hepatitis patients, 12 patients with chronic renal failure and 4 cirrhosis) were infected with variants of type 3 of HCV. None of the cirrhotic patients and patients with chronic renal failure, in the present study, were infected with type 1 of HCV. While PCR-RFLP, typing was rapid in conjunction with the primers used for RT-PCR, NS5 typing was helpful in determining the subtype. There was good correlation between the two typing methods and this method can be used as a cost-effective method for studying large number of samples. The study shows that predominant genotypes of HCV in South India include type 1 and 3. Type 3 seems to be transmitted nosocomially as suggested by the results in patients with chronic renal failure, as these patients are exposed to multiple medical interventions.