ABSTRACT
There were 1,544 healthy people requested for hepatitis B vaccinations and blood testing from the Health Service Unit in the Siriraj Hospital’s Centennial Anniversary Fair from April 27, to May 7, 1988. The ages of those 689 people ranged from 1-70 years received hepatitis B vaccination. 52.8% were children under 10 years of age. The prevalence of hepatitis B infection among 1,214 people of 6-82 years were studies. HBs Ag and anti-HBc positive were found in 9.3% of the population studied 13.7% in male, and 6% in female. Only 31.2% of this group was immuned (anti-HBs and anti-HBc positive). The discrepant markers were found as followings: 9.6% had anti-HBc positive solely, 3.6% had anti-HBc positive solely and 0.3% were positive for all 3 markers. The percentage among those with neither antigen nor antibody was 45.9%.