title: Distribution of the different genotypes of HCV among patients attending a tertiary care hospital in south India.
abstract: BACKGROUND
  Genotyping of the hepatitis C virus (HCV) and assessment of viral load is important for designing therapeutic strategies and region specific diagnostic assays.
  
  
  OBJECTIVE
  To determine the distribution of HCV genotypes among patients attending a tertiary care hospital in south India, and to correlate this with viral load.
  
  
  METHODS
  Ninety HCV RNA positive patients were recruited for the study. HCV genotyping was carried out using type-specific primers from the core region of the viral genome [J. Clin. Microbiol. 35 (1997) 201]. Viral load estimations were carried out using the Amplicor HCV Monitor (Versions 1.5 and 2, Roche Diagnostics, Branchburg, NJ, USA). Clinical details were elicited from patients' hospital records.
  
  
  RESULTS
  Genotype 3 was detected most frequently (62.2%) followed by infection with HCV genotype 1 (18.8%). There was no significant difference seen in alanine aminotransferase (ALT) values between the two genotypes. Genotype 1 was associated with a significantly higher viral load as compared with genotype 3 (P=0.001). Parenteral transmission accounted for 61% of all infection caused. Infection with genotype 1 was significantly associated with a history of haemodialysis (P=0.01). Genotype 3 was detected more frequently in patients from east India, as compared with its detection in patients from south India (P=0.004). Similarly, genotype 1 was detected with greater frequency in individuals from south India as compared with patients from east India (P=0.004). The concordance between Ohno's genotyping assay and nucleotide sequencing, for genotypes 1 and 3, was 75%.
  
  
  CONCLUSIONS
  HCV genotypes 1 and 3 accounted for 81% of HCV infections in patients from this geographical region. HCV genotype distribution showed regional differences and genotype 1 was associated with higher viral loads. Parenteral transmission was the major route for acquisition of HCV infection. Ohno's type-specific primer based genotyping assay can be used for distinguishing between HCV genotype 1 and non-1 HCV genotypes in laboratories that do not possess nucleotide sequencing facilities.
authors.affiliation: Department of Clinical Virology, Christian Medical College and Hospital, Vellore, Tamil Nadu 632004, India.
authors.forename: Sukanya
authors.initials: S
authors.lastname: Raghuraman
authors.forename: R V
authors.initials: RV
authors.lastname: Shaji
authors.forename: Gopalan
authors.initials: G
authors.lastname: Sridharan
authors.forename: Sujatha
authors.initials: S
authors.lastname: Radhakrishnan
authors.forename: George
authors.initials: G
authors.lastname: Chandy
authors.forename: B S
authors.initials: BS
authors.lastname: Ramakrishna
authors.forename: Priya
authors.initials: P
authors.lastname: Abraham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D015415:Biomarkers; D002648:Child; D003430:Cross-Sectional Studies; D018562:Disease Transmission, Infectious; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006526:Hepatitis C / Q000201:enzymology / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D006782:Hospitals, Special / Q000706:statistics & numerical data; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics*; D006435:Renal Dialysis / Q000009:adverse effects; D017423:Sequence Analysis, RNA; D065227:Transfusion Reaction; D019562:Viral Load
chemical_list: D015415:Biomarkers; D012367:RNA, Viral; D000410:Alanine Transaminase