Seroepidemiology of Hepatitis A in Taejon, Korea 1996

ABSTRACT

PURPOSE: We experienced an outbreak of hepatitis A in Taejon, Korea for the summer of 1996. Recently a shift in hepatitis A incidence from children to adults has been well noted in Korea. For the purpose of possible measures in preventing hepatitis A, we studied a seroepidemiology of hepatitis A in Taejon. METHODS: We measured IgG anti-HAV antibody (HAVAB MEIA, Abbott) from 722 randomly collected sera of neonates (cord blood) to 70-years-olds and older. RESULTS: The prevalence of anti-HAV in neonates was 90.2%, 80.0% in 1-6 months, 34.7% in 7-12 months, 8.7% in 1-5 years, 0% in 6-10 years, 1.8% in 11-15 years, 29.3% in 16-20 years, 62.6% in 21-30 years, and nearly 100% in 31 years and older. In order to evaluate the time lossed transferring anti-HAV IgG from the mother, we analyzed 142 children aged 1 month to 24 months with 2-month intervals. The results were 81.3% in 1-2 months, 84.2% in 3-4 months, 80.0% in 5-6 months, 55.6% in 7-8 months, 23.1% in 9-10 months, 33.3% in 11-12 months, 8.3% in 13-14 months, 16.7% in 15-16 months, 0% in 17-18 months, 0% 19-20 months, 14.3% in 21-22 months, and 0% in 23-24 months. In order to estimate the rough conversion time of anti-HAV in the Taejon population, we analyzed 99 adults in their twenties with 2-year intervals. The positive rate of anti-HAV was 41.7% in 21-22 years, 69.2% 23-24 years, 63.0% in 25-26 years, 61.5% in 27-28 years,and 100% in 29-30 years. CONCLUSION: This study showed that the prevalence of hepatitis A in children has changed compare to the past 10-20 years and the possibility of another outbreak and/or increasing incidence of apparent hepatitis A in adults in the Taejon area or any other place in Korea is possible. The preventive modalities including hepatitis A vaccination or immune serum globulin against children and young adults at risk is necessary.