Genotypes of hepatitis C virus in the Indian sub-continent: a decade-long experience from a tertiary care hospital in South India.
BACKGROUND
Hepatitis C virus (HCV) is a leading cause of chronic liver disease (CLD) that can progress to cirrhosis and hepatocellular carcinoma. Genotypes of HCV can vary in pathogenicity and can impact on treatment outcome.


OBJECTIVE
To study the different genotypes among patients with HCV related CLD attending a tertiary care hospital in south India during 2002-2012.


METHODS
Study subjects were those referred to clinical virology from the liver clinic. Genotyping was performed using the genotype specific core primers in nested polymerase chain reaction (PCR), 5' non-coding regions based PCR- restriction fragment length polymorphism and NS5B sequencing methods. With the latter method, obtained sequences were compared with published GenBank sequences to determine the genotype.


RESULTS
Of the 451 samples tested, HCV genotype 3 was found to be the most predominant (63.85%). Other genotypes detected were genotype 1 (25.72%), genotype 2 (0.002%), genotype 4 (7.5%) and genotype 6 (2.7%). Genotype 3 was the common genotype in patients from Eastern India while genotype 1 and 4 were mainly seen in South Indian patients. Genotype 6 was seen exclusively in patients from North-Eastern India. Two other patients were infected with recombinants of genotype 1 and 2.


CONCLUSIONS
In this study spanning a decade, HCV genotype 3 and genotype 1 were found to be the predominant genotypes in the Indian sub-continent. Genotype 4 and genotype 6 appeared to show some geographic restriction. A continued monitoring of HCV genotypes is essential for the optimum management of these chronically infected patients. In addition, knowledge of circulating genotypes could impact on future vaccine formulations.
Department of Clinical Virology, Christian Medical College, Vellore, Tamil Nadu, India.
J
J
Christdas
J
J
Sivakumar
J
J
David
H D J
HD
Daniel
S
S
Raghuraman
P
P
Abraham
D020121:5' Untranslated Regions; D014644:Genetic Variation; D005838:Genotype; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D007194:India / Q000453:epidemiology; D017720:Molecular Epidemiology; D058974:Phylogeography; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012367:RNA, Viral / Q000235:genetics; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D062606:Tertiary Care Centers; D017361:Viral Nonstructural Proteins / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase
D020121:5' Untranslated Regions; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase