Prevalence of HBV and HCV among outpatients in the Plovdiv region of Bulgaria, 2010-2011.

Viral hepatitis, particularly hepatitis B and C, are diseases with worldwide distribution that present a significant public health problem. Seroprevalence studies allow assessment of the extent of the disease burden, the identification of populations at risk and the monitoring trends over time. A multi-center seroprevalence study, carried out in Bulgaria (covering the five largest cities - Sofia, Plovdiv, Varna, Pleven, and Stara Zagora) in 1999-2000 estimated a crude seroprevalence rate of 3.9% for HBsAg and 1.3% for anti-HCV. A decade later, comparable rates were observed in a study including 865 outpatients consulting a clinical laboratory in Plovdiv, the second largest administrative region in Bulgaria. The crude seroprevalence rate measured for hepatitis B (HBsAg) was 3.9%. The HBsAg prevalence rate in individuals ≤19 years of age (targeted by vaccination) was significantly lower compared to the rate in adults ≥20 years of age -1% versus 4.8%. The lack of dynamics in the overall level of HBsAg carriers is likely related to the excessively low hepatitis B vaccine coverage in individuals, born before the introduction of the universal vaccination of newborns in August 1991. Anti-HCV antibodies were detected in 0.7% of the subjects.