The hidden burden of viral hepatitis B and C in healthcare settings: a cross-sectional study of seroprevalence, predictors, and occult infection

Abstract

Background Bloodborne viral hepatitis B and C remain critical occupational hazards for healthcare workers (HCWs). Current mandatory screening in some countries, including Russia, relies solely on hepatitis B surface antigen (HBsAg) detection, which may overlook occult infections. This study aimed to evaluate the prevalence, predictors, and occupational risks of HBV (including occult HBV infection) and HCV among HCWs in multidisciplinary facilities. Methods A cross-sectional observational study of 1,643 HCWs and auxiliary staff was conducted. Blood serum samples were tested for anti-HBc, anti-HBs, and anti-HCV antibodies using ELISA. Seropositive individuals underwent real-time PCR testing to detect HBV DNA and HCV RNA. Multivariable logistic regression was used to identify independent predictors of seropositivity. Results Anti-HBc IgG was detected in 36.6% of HCWs, demonstrating a strong age gradient (aOR = 1.55 per 10 years of age; p < 0.001), rising from 12.4% in those under 30 to 50% in those over 60. Anti-HBs levels ≥10 mIU/mL were observed in only 54.8% of HCWs, dropping to 29.7% at a stricter threshold (>100 mIU/mL). High anti-HBs titers (100–1,000 mIU/mL) were strongly associated with anti-HBc positivity (aOR = 4.65; p < 0.001). Occult hepatitis B infection (OBI) was detected in 3.1% (95% CI 0.85–7.73%) of tested anti-HBc-positive HCWs, who exhibited lower median anti-HBs concentrations compared to PCR-negative counterparts (7 vs. 165 mIU/mL; p = 0.003). HBV DNA was detected in 4 of 129 HBsAg-negative, anti-HBc-positive participants (3.1%), a finding consistent with possible occult HBV infection. Notably, 75% of OBI cases were classified as low occupational risk. Anti-HCV prevalence was 5%, but HCV RNA was detected in only 3.6% of seropositives (overall prevalence 0.18%). Logistic regression for anti-HCV showed poor predictive value (AUC 0.546, p = 0.68). Conclusion Despite vaccination efforts, a high rate of HBV exposure and waning seroprotection persist among HCWs. The detection of OBI and active HCV in “low-risk” personnel highlights the limitations of current HBsAg-only screening. Epidemiological surveillance should transition to active monitoring of anti-HBc / anti-HBs status and targeted PCR screening, alongside strict adherence to standard precautions by all staff.