Seroepidemiological analysis of hepatitis B among children aged 1-14 in 3 counties of Guangdong province in 2013

Abstract

To investigate the epidemic status of Hepatitis B in children aged 1-14 in 3 counties of Guangdong province in 2013, and to evaluate the effect of hepatitis control in children aged 1-14 after hepatitis B vaccine was integrated into the national immunization program in 2002 and catch-up vaccination was conducted from 2009 to 2011. A multi-stage stratified random sampling was designed to survey 1 621 children aged 1-14 in rural area of Nanxiong county, Haifeng county and Xinxing county by questionnaires including general information, medical history and risk factors. The samples were tested with chemiluminescence method to detect hepatitis B virus (HBV) surface antigen (HBsAg), antibody to HbsAg (anti-HBs) and antibody to HBV core antigen (anti-HBc). Chi-square test was used to compare the positive rate of HBV serum markers in different age groups, vaccine histories, birth weight and HBV infection status of mother. Among the children aged 1-14 in 3 counties rural regions of Guangdong province, the positive rate of HBsAg, anti-HBs, and anti-HBc was 1.11% (18/1 621), 60.69% (982/1 618) and 1.92% (31/1 617), respectively. The HBsAg positive rate of vaccinated children (0.84%, 13/1 547) was lower than that of unvaccinated children (1/13) or children with unknown vaccination status (6.56%, 4/61) (χ² = 22.64, P < 0.001). The HBsAg positive rate (0.45%, 5/1 118) of the children with birth-dose given within 24 hours was lower than those that of children given beyond 24 hours (2.63%, 61/190) (χ² = 10.21, P < 0.001). The HBsAg positive rate (5/18) of children with birth weight under 2 kilogram was higher than that of children with birth weight above 2 kilogram (0.78%, 12/1 548) (χ² = 120.8, P < 0.001). The HBsAg positive rate of children born to HBsAg-positive mothers (2.80%, 3/107) was higher than that of children born to HBsAg-negative mothers (0.21%, 1/470) (χ² = 8.50, P = 0.004). With the age increasing, the coverage and timely birth-dose coverage of Hepatitis B vaccine (HepB) decreased, and the positive rate of anti-HBs gradually decreased. After the catch-up vaccination was conducted in unvaccinated children aged 1-14 years from 2009 to 2011, the HBsAg and anti-HBc positive rate decreased, while the anti-HBs positive rate increased significantly.