Genetic Monitoring as a Component of Hepatitis C Surveillance

Abstract

Background: The hepatitis C virus is known for its high spontaneous mutation rate and genetic heterogeneity. Genotype distribution varies greatly between different regions of Russia. This phenomenon reflects autonomous nature of the epidemic process of the hepatitis C infection. Objective: To investigate and analyze the diversity of genetic variants of the hepatitis C virus currently circulating in the city of Nizhny Novgorod. Material and methods: Official hepatitis C incidence data for the Nizhny Novgorod Region were analyzed retrospectively. From the blood serum bank, we obtained 142,254 serum samples from examined outpatients and patients admitted to hospitals for noninfectious diseases. Laboratory testing included detection of the following markers for hepatitis C virus infection: serum anti-HCV IgM and IgG, antibodies to structural and non-structural viral proteins. A part of seropositive samples was tested for HCV RNA and genotyped by real-time PCR. Results: We observed stabilization of the trend in the incidence of acute hepatitis C in Nizhny Novgorod and a steady decrease in the incidence of newly diagnosed chronic hepatitis C. The antibody serology tests showed that the prevalence of anti-HCV was 3.1 ± 0.1 per 100 examined persons. HCV RNA was detected in 1.9 ± 0.1 % of adults, the most affected being those aged 40–49 years. Subtypes 1b and 3a prevailed while subtype 1a, genotype 2, and mixed variants were rare. Conclusion: Introduction of advances in genetic diagnosis into the system of epidemiologic hepatitis C surveillance is determined by the relevance of conducting a comprehensive examination of people infected with HCV in order to monitor circulation of hepatitis C virus genotypes/subtypes and to understand the evolution and epidemiological features of the disease in different areas.