Current epidemiological, molecular and genetic characteristics of enteric viral hepatitis in Russia

Rationale: Enteric hepatitis including hepatitis A and hepatitis E are globally prevalent diseases with large social and economic burden. In some patient categories these may be lethal. Hepatitis A (HAV) and hepatitis E (HEV) viruses are heterogeneous and have high geographic variability.Aim: To assess current epidemiological, molecular and genetic characteristics of enteric viral hepatitis in the Russian Federation.Materials and methods: We analyzed the data of the State statistical reports on the incidence of infectious diseases in the Russian Federation and of the analytical tables. Also, genotype identification of the HAVs isolated from 31 patients living in St. Petersburg was performed with specific primers flanking VP1/2A region.Results: In the last 20 years (from 1997 to 2017), the epidemic process of hepatitis A in the Russian Federation has been changing substantially, including first of all its intensity and age distribution of the patients. Unlike hepatitis A, the official registration of hepatitis E in the Russian Federation was initiated only in 2013. During the analyzed time period, the incidence of hepatitis E varied from 0.06 to 0.08⁰⁄₀₀₀₀, with non-significant trend towards its increase in 2017. It has been found that from 2013 to 2015, two sub-genotypes of the virus (1a and 1b) circulated in St. Petersburg, with prevailing genotype 1a. The local cases of hepatitis E were caused by HEV genotype 3, whereas the imported cases, by HEV genotype 1.Conclusion: In the Russian Federation, there has been a long-standing and stable trend toward decreased incidence of hepatitis A. However this has led to weakening of collective immunity, mainly among the adult population. In combination with poor levels of municipal infrastructures and services in some territories, this may lead to an increase of the hepatitis A incidence. Despite that Russia is a non-endemic region for hepatitis E, local cases of the disease are increasingly identified.