title: Impact of the Expanded Program of Immunization against hepatitis B infection in school children in Malaysia.
abstract: The implementation of the Expanded Program of Immunization (EPI) in 1989 has dramatic impact on hepatitis B virus (HBV) infection in school children in Malaysia. A cross-sectional seroprevalence study of HBV infection in 190,077 school children aged 7-12 years from 1997 to 2003 showed a steady decline of HBV surface antigen (HBsAg) prevalence rate from 2.5% for children born in 1985 to 0.4% among school children born in 1996. The overall prevalence of HBsAg was 0.6%, 0.7% in males and 0.6% in females. Over 92.7% of school children had been vaccinated with HBV vaccine, in which 93.7% were vaccinated under the EPI and 6.3% on voluntary basis. The school children vaccinated under EPI had a 0.4% HBsAg carrier rate, which was significantly lower than school children vaccinated on a voluntary basis (HBsAg carrier rate 1.3%) and non-vaccinated school children (HBsAg carrier rate 2.7%), suggesting that HBV vaccination of infants was the most effective measure in preventing vertical transmission of HBV in the hyperendemic region.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia. kpng@um.edu.my
authors.forename: K P
authors.initials: KP
authors.lastname: Ng
authors.forename: T L
authors.initials: TL
authors.lastname: Saw
authors.forename: A
authors.initials: A
authors.lastname: Baki
authors.forename: K
authors.initials: K
authors.lastname: Rozainah
authors.forename: K W
authors.initials: KW
authors.lastname: Pang
authors.forename: M
authors.initials: M
authors.lastname: Ramanathan
mesh_terms: D002353:Carrier State / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006801:Humans; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D032541:Mass Vaccination; D016036:Seroepidemiologic Studies; D013334:Students
chemical_list: D006514:Hepatitis B Surface Antigens