Seroepidemiology of Hepatitis A in South Korea: A Nationwide Study by the Eone Reference Laboratory

Background: We evaluated the recent prevalence of serologic markers of hepatitis A virus (HAY) in South Korea. Methods: The study data were the results of 60 126 anti-HAY (total) tests and 30 786 anti-HAY IgM tests that were performed during April 2009 through March 2010 by the Eone Reference Laboratory at the request of 1935 institutions throughout Korea. Results: The overall positivity rate was 51.06% on the anti-HAY (total) test and 11.20% on the anti-HAY IgM test. As compared with the other age groups the rate of anti-HAY (total) positivity was significantly lower (P < 0.001), and the rate of anti-HAY IgM positivity was significantly higher (P < 0.001), among Koreans aged 11 to 40 years. The seroprevalence of anti-HAY IgM significantly differed according to region but not by referral date. Conclusions: This was the largest nationwide study in South Korea by 1 laboratory, and it provides useful recent baseline data on hepatitis A in Asia. The findings suggest that active immunization of younger Koreans should be made a priority.