A Territorywide Prevalence Study on Blood-Borne and Enteric Viral Hepatitis in Hong Kong

Viral hepatitis epidemiological data are important for the World Health Organization plan of eliminating viral hepatitis. We aimed to document the prevalence of viral hepatitis A to E in Hong Kong.

This community-based study was open to all Hong Kong Chinese citizens aged ≥18 years. Baseline data and risk factors were collected. Hepatitis A-E serology was measured, including hepatitis B e antigen, antibodies to hepatitis B e antigen, antibodies to hepatitis D, hepatitis B virus (HBV) DNA for hepatitis B surface antigen (HBsAg)-positive participants, and antibodies to hepatitis B surface antigen and antibodies to hepatitis B core antigen (anti-HBc) in HBsAg-negative participants. Hepatitis C virus (HCV) RNA and genotypes were determined in anti-HCV-positive participants.

A total of 10 256 participants were recruited from February 2015 to July 2016. Overall HBsAg seroprevalence was 7.8% (95% confidence interval [CI], 7.3%-8.3%), which was reduced significantly with HBV vaccination (odds ratio, 0.15 [95% CI, .11-.21]). Among HBsAg-negative participants, anti-HBc seroprevalence increased from 5.4% (<26 years) to 60.1% (>65 years). No hepatitis D virus (HDV) cases were detected. Anti-HCV positivity was 0.5% (95% CI, .3%-.6%). Prevalence of antibodies to hepatitis A virus (anti-HAV) and hepatitis E virus (anti-HEV) was 65.2% (95% CI, 64.2%-66.1%) and 33.3% (95% CI, 32.4%-34.2%), respectively, and were influenced by age, family income, and being born in mainland China.

HBV seroprevalence remained high despite universal vaccination. High anti-HBc seroprevalence underlines the potential issue of HBV reactivation during profound immunosuppression. HCV and HDV remained uncommon. Anti-HAV seroprevalence had decreased whereas anti-HEV seroprevalence had risen.