[Epidemiological survey on the hepatitis C virus and its genotyping analysis in Henan province in 2012].

Objective: To investigate the prevalence and distribution of hepatitis C virus (HCV) genotypes in Henan province in 2012.

Methods: A total of 32 203 permanent residents (1 to 74 years old) in Henan were recruited using multi-stage random samping method from March to June 2012. All participants were asked to complete a questionnaire to collect demographic information, past medical history and the exposure history of risk factors. A blood sample of 5 ml was collected at the same time. The condition of anti-HCV and HCV RNA was determined through the ELISA test and nested RT-PCR. HCV RNA positive samples were further subject to the nonstructural protein 5 region (NS5B) gene amplification and sequencing. The sequence was amplified for the phylogenetic tree and genetic analysis. The differences of the positive rate of anti-HCV and HCV RNA and the HCV genetic subtype distribution in different respondents'characteristics were analyzed.

Results: Among 32 203 subjects, the overall positive rate of anti-HCV and HCV RNA were 0.48% (153/32 203) and 0.24% (78/32 203), in which men were 0.42% (65/15 634), and 0.23% (36/15 634), and women were 0.53% (88/16 569) and 0.25% (42/16 596). The differences between men and women were not statistically significant (χ(2) values were 2.26, 0.18, respectively, both P values > 0.05). The results of NS5B genotyping and molecular evolution analysis showed that there were six subtypes in the 71 HCV RNA positive samples.In those six subtypes, the proportion of genotypes 1b, 6a, 3a, 2a, 3b and 1a were 56.3% (40/71), 19.7% (14/71), 11.3% (8/71), 8.5% (6/71), 2.8% (2/71) and 1.4% (1/71), respectively. The HCV genetic subtypes of infestor were mainly present with two branches of 1b and 6a, and the two subtypes Bootstrap values were 0.95.

Conclusion: The prevalence of HCV infection was high in Henan. The major HCV genotypes in patients with HCV infection were 1b and 6a.