Seroprevalence of hepatitis E virus in Hong Kong, 2008-2009.

The public health impact of hepatitis E virus (HEV) infection varies across the world. An HEV vaccine has been recently approved for clinical use in China. Population-specific seroprevalence data are essential for cost-effective assessment of vaccination programs. Here, a cross-sectional study was performed to provide an update on the local seroprevalence of HEV. An archive of serum samples submitted for virological investigation between 2008 and 2009 to a general hospital was used. A total of 450 samples with equal numbers from each gender covering the age groups from 1-10 to >80 years (25 samples per group) were tested for HEV immunoglobulin G (IgG) by enzyme-linked immunoassay. Age- and gender-specific seroprevalence were determined. The HEV IgG positive rate increased from 8% among 1-10 years to 56% among >80 years. The increase in prevalence was constant throughout all age groups without a steeper slope or plateau observed from any age group. The overall positive rate among males was significantly higher than among females (32.9% vs. 24.4%, P = 0.048). The best-fitted seroprevalence curves also suggested a higher positive rate for males across all age groups. Increased HEV IgG positivity was noted in comparison with historical local studies. Collectively, the prevalence of HEV in Hong Kong has increased over the past decade. A large proportion of the population is still susceptible to infection, and all age groups are at risk. Territory-wide vaccination program should be considered.