Epidemiology of hepatitis C in the Moscow Region: data from the Moscow Regional Registry and screening for HCV antibodies

Background: Epidemiological characteristics of chronic hepatitis C virus (HCV) infection presented in the literature are not representative for the real situation with its incidence and prevalence in the Russian Federation. In the Moscow Region, which is the second largest population in the Russian Federation (7.2 million people), the Moscow Regional Registry of patients with hepatic disorders has been continuously maintained since 2010, as well as screening programs for anti-HCV positive individuals. Analysis of this data allows for generalization of the results obtain to the general population and for description of the prevalence of the infection among adult population of the Russian Federation. Aim: To analyze the epidemiological situation with chronic hepatitis C in the Moscow Region. Materials and methods: We analyzed data from the Moscow Regional Registry of patients with hepatic disorders as per April 2016, as well as the results of large scale screening of the population of the Moscow Region with oral express test for anti-HCV antibodies (OraQuick HСV Rapid Antibody Test). Based on the registry, we assessed the following parameters of the patient cohort with chronic HCV infection (n = 17 182): age, gender, HCV genotype, grade of liver fibrosis, allele variants of interleukin 28В. Within the large scale screening program among the population of the Moscow Region, 1447 individuals from 6 districts of the region were screened for anti-HCV antibodies. Results: As per April 2016, the proportion of patients with chronic viral hepatitis in the Registry was 75.3% (n = 12 938 of 17 182). The vast majority of them (80.3%, or n = 10 393) had chronic hepatitis C, with 84% (n = 8726) of referrals were patients of productive age (from 20 to 50 years). 8.4% (n = 873) of all HCV infected patients had liver cirrhosis. Although the proportion of patients with cirrhosis was negligibly low (< 1.5%) in patients below 30 years of age, it was progressively increasing with age, with a maximum of 23.8% in those above their 50-es. As far as the HCV genotype distribution is concerned, it was as follows: genotype 1, 54.1% (n = 5622) of patients, genotype 2, 7.2% (n = 747), genotype 3, 38.4% (n = 3990). According to the results of assessment of IL28B genetic polymorphisms (n = 3212), СС rs12979860, which is associated with the most favorable sensitivity to interferon α, was found in 27.5% (n = 883), СТ allele, in 58.4% (n = 1876), and ТТ in 14,1% (n = 453). Prevalence of HCV infection in the Moscow Region, assessed by the screening program, is 1.38% of adults, or 77 200 anti-HCV positive persons, whereas estimated number of patients with chronic hepatitis C may amount to 54 000 to 61 700. Conclusion: HCV infection is the most prevalent among other viral hepatites in the Moscow Region (80.3%), and the largest numbers of infected individuals are of productive age. Almost three quarters of these patients are referred for medical care at the stage of minimal liver injury, and antiviral therapy can be used on an elective basis. Knowing the proportion of patients with liver cirrhosis (8.4%) allows for planning of the need in emergency treatments. The true prevalence of HCV infection estimated from the results of the screening program is at least 5-fold higher than that in the Registry. This indicates the necessity to upgrade the system of primary assessments. In particular, it seems reasonable to include detection of anti-HCV antibodies into the list of obligatory screening laboratory tests.