[Hepatitis B surface antigen and antibody positive rates of children and adolescents in Jeju].

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 hemagglutination (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.