Background/Aims
Korea has been an endemic area of Hepatitis B infection. Recently, the Hepatitis B
carrier population has been significantly decreasing because of Hepatitis B vaccination. The aim of this study
was to analyse the Hepatitis B surface antigen (HBsAg) and the Hepatitis B surface antibody (anti-HBs)
positive rates of children and adolescents in Jeju. Methods: From January 2000 to August 2002, seropositivity
of HBsAg and anti-HBs were evaluated by enzyme immunoassay (EIA) in 1,653 pediatric patients. From April
2002 to August 2002, seropositivity of HBsAg and anti-HBs were evaluated by reversed passive
hemaglutination (RPHA) in 2,532 students. From July 1994 to February 2003, seropositivity of HBsAg was
evaluated by EIA in 1,013 pregnant women. Results: The positive rates of HBsAg and anti-HBs of children
and adolescents in Jeju were 2.1% and 70.9%, respectively. The positive rates of HBsAg of pregnant women
in Jeju was 4.7% and that of HBeAg in HBsAg positive pregnant women was 38.1%. In children born after
1995, as age increased, HBsAg seropositivity increased significantly and anti-HBs seropositivity decreased
significantly. There was no significant difference in testing HBsAg positivity between the RPHA and the EIA
tests, but testing anti-HBs positivity by EIA was significantly higher than by RPHA. Conclusions: To reduce
HBsAg positive rate, regular testing for anti-HBs by EIA may be indicated until at least 15 years after the
primary vaccination schedule, and booster vaccination may be indicated in subjects whose anti-HBs titer was
under 10 mIU/mL. 29.1% of children and adolescents in Jeju, therefore, may need to be revaccinated.(Korean
J Hepatol 2003;9:304-314)
