Sero-epidemiology and risk factors of positive hepatitis B surface antigen amongst Chinese adolescents.

This paper reports the prevalence rate of hepatitis B antigen (HBsAg) amongst the Hong Kong Chinese adolescents (age 11 to 19), and the risk factors associated with HBsAg positive. The study is cross sectional and 1,580 students were randomly selected from 12 secondary schools in four regions of Hong Kong. For those subjects who agreed to participate and were randomly selected, their blood was tested for HBsAg and anti-HBs. The overall prevalence of HBsAg positive was reported to be 5.8% (7.9% in male and 4.1% in female), lower than 8.1% in 1978. Males, those born in Mainland China and family history of carriers had higher prevalence of HBsAg positive (7.9% vs 4.1%, 12.2% vs 4.7%, 52.9% vs 3.8% respectively) with statistical significance. Males and those born in mainland China were found to have significantly higher odds ratio 1.8 (95% CI. 0.98-3.52) and 4.4 (95% CI. 2.2-8.8) respectively of HBsAg positive by multivariate analysis. Findings suggest that family history of carriers and those born in endemic area are at a higher risk. Therefore it is worthwhile to consider vaccination programme for adolescents to reduce the carrier rate, and to also reduce the injection amongst the adults by horizontal transmission.