Epidemiological Characteristics of Chronic Viral Hepatitis in Kazakhstan: Data from Unified Nationwide Electronic Healthcare System 2014–2019

BACKGROUND: Viral hepatitis is the leading cause of hepatic cirrhosis and liver-related mortality, yet there are no countrywide epidemiological studies available to date in Kazakhstan. The aim of the study was to perform an estimation of mortality, prevalence and incidence of Hepatitis B and C infections and liver-related complications. METHODS: Using centralized healthcare data from the Unified National Electronic Health System (UNEHS) for the period 2014–2019, a total of 82,700 registered patients with chronic viral hepatitis B (HBV), C (HCV) and D (HDV) have been extracted based on ICD −10 codes. Crude rates of incidence, prevalence and mortality, as well as age-, sex- and year-specific rates of incidence and mortality per 100,000 population were estimated. Unadjusted and adjusted hazard ratios were estimated using Cox proportional hazards regression modeling. RESULTS: For the total number of 82,700 patients, 56.6% were represented by chronic HCV infection and 43.4% by HBV infection. The prevalence of coinfection was 10% for HBV+HDV and 3.5% for HBV+HCV. Both HBV and HCV were more prevalent among female patients (56%) and among Kazakh ethnic group (64.8%). Males with HBV had a higher probability of death than females; this trend was stronger among male patients with HCV. Russian ethnic groups infected with HBV had a higher risk of death compared to Kazakh and other ethnic groups. Whereas in HCV-infected patients, Russian ethnic group and other ethnic group had similar risk for death, but higher compared to Kazakhs. CONCLUSION: During the 2014–2019 period, prevalence, incidence and mortality from chronic HBV and HCV infections increased. Despite the disproportionately higher infection rate among females with chronic viral hepatitis, all-cause mortality was more than two-fold higher among males. Higher death rates in Russian ethnic group compared to other ethnicities need to be evaluated in further studies for other confounding factors and associated comorbidities in this group.