title: Distribution frequency of hepatitis C virus genotypes in 2231 patients in Iran.
abstract: OBJECTIVE
  Given the importance of frequency distribution of HCV genotypes, we studied genotypic distribution of HCV in Iran. In this cross-sectional study, 2231 patients with hepatitis C who presented in hepatitis clinics in Tehran were investigated for HCV genotypes.
  
  
  METHODS
  Genotyping was performed by genotype specific primers.
  
  
  RESULTS
  The highest frequency was for genotype 1a, with 886 (39.7%) of subjects. Genotype 3a and 1b were the other frequent genotypes, with 613 (27.5%) and 271 (12.1%) subjects, respectively. Of the samples, 401 (18%) had an undetermined genotype. Mixed genotypes were also found in 33 samples (1.6%). Genotype 1b frequency in patients under 20 years old was 10.2%, while its frequency in patients over 60 years old was 18.5%. Genotype 1b frequency significantly increased by age (P = 0.02).
  
  
  CONCLUSIONS
  This study indicates that the dominant HCV genotype among patients living in Tehran was 1a.
authors.affiliation: Iran University of Medicine, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Keyvani
authors.forename: Amir H M
authors.initials: AH
authors.lastname: Alizadeh
authors.forename: Seyed M
authors.initials: SM
authors.lastname: Alavian
authors.forename: Mitra
authors.initials: M
authors.lastname: Ranjbar
authors.forename: Saeed
authors.initials: S
authors.lastname: Hatami