Hepatitis B Virus Infection in Children and Adolescents in a Hyperendemic Area: 15 Years after Mass Hepatitis B Vaccination

6 November 2001 | Volume 135 Issue 9 | Pages 796-800

Background: Hepatitis B virus (HBV) infection is hyperendemic in Taiwan. Before universal HBV immunization was started in Taiwan in 1984, the carrier rate for hepatitis B surface antigen (HBsAg) was 15% to 20% in the general population.

Objective: To quantify the population impact of a mass vaccination program for HBV 15 years after its implementation.

Design: Descriptive analysis of serologic markers of HBV in healthy children and adolescents.

Setting: Chung-Cheng District, Taipei City, Taiwan, in 1999.

Participants: 1357 persons younger than 15 years of age, who were born after the implementation of universal HBV vaccination, and 559 persons 15 to 20 years of age, who were born before the program began.

Measurements: Repeated serologic surveys similar to those done before and 5 and 10 years after the national vaccination program was implemented. All participants were tested for serum HBsAg, its antibody (anti-HBs), and hepatitis B core antibody (anti-HBc).

Results: During the 15 years since the vaccination program was implemented, the prevalence of HBsAg among persons younger than 15 years of age decreased from 9.8% in 1984 to 0.7% in 1999; among persons 15 to 20 years of age, the 1999 prevalence of HBsAg was 7% (P < 0.001). Hepatitis B core antibody seropositivity, which represents HBV infection, was found in 2.9% of persons younger than 15 years of age and in 20.6% of persons 15 to 20 years of age (P < 0.001); in the same age groups, the rate of anti-HBs seropositivity was 75.8% and 70.7%, respectively (P = 0.02).

Conclusions: Universal vaccination significantly decreased the HBV carrier rate and infection rate among children and adolescents born since the program began. By decreasing the carrier pool, continuation of the national HBV immunization program should prevent HBV infection in the children of Taiwan, and, subsequently, adults as well.

Author and Article Information

From National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei, Taiwan.

Acknowledgments: The authors thank Dr. Ching-Fan Chung for assistance with statistical analysis. They also thank Ms. Su-Yau Kao, Ms. Alice Hsiu-Yu Lin, Ms. Jia-Bao Pang, and Ms. Jin-Le Shan for excellent technical assistance in data collection, case enrollment, and serologic assays.

Grant Support: By the Department of Health, Executive Yuan, Taiwan (grants DOH-89-DC-1017 and DOH-88-DC-1001).

Requests for Single Reprints: Mei-Hwei Chang, MD, Department of Pediatrics, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei 100, Taiwan; e-mail, mhchang{at}ha.mc.ntu.edu.tw.

Current Author Addresses: Drs. Ni, Chang, Huang, Chen, Hsu, Chiu, Tsai, and Chen: National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei 100, Taiwan.

Author Contributions: Conception and design: Y.-H. Ni, M.-H. Chang.

Analysis and interpretation of the data: Y.-H. Ni, M.-H. Chang.

Drafting of the article: Y.-H. Ni, M.-H. Chang.

Critical revision of the article for important intellectual content: Y.-H. Ni, M.-H. Chang, L.-M. Huang, H.-L. Chen, H.-Y. Hsu, T.-Y. Chiu, D.-S. Chen.

Final approval of the article: Y.-H. Ni, M.-H. Chang, L.-M. Huang, H.-L. Chen, H.-Y. Hsu, T.-Y. Chiu, K.-S. Tsai, D.-S. Chen.

Provision of study materials or patients: Y.-H. Ni, M.-H. Chang, L.-M. Huang, T.-Y. Chiu, K.-S. Tsai, D.-S. Chen.

Obtaining of funding: Y.-H. Ni.

Collection and assembly of data: Y.-H. Ni, M.-H. Chang.