Waning of anti-HAV immunity in Shijiazhuang prefecture, Hebei province, China: a comparison of seroprevalence between 1992 and 2011.

Abstract

OBJECTIVE:

To study the epidemiological patterns of hepatitis A, and immunity of entire population in Shijiazhuang prefecture, Hebei province, a former hyper-endemic area in north China.

METHODS:

Cross-sectional, seroprevalence surveys with two-stage cluster sampling were conducted among population older than 2-year between 1992 and 2011. During the 2011 serological survey, blood samples from infants <18 months without hepatitis A immunization history were also collected to determine maternal anti-HAV antibody. Serum samples were tested for anti-HAV antibody by domestic reagent or Abbott reagent. Viral hepatitis incidence rates and gross domestic product data were derived from local governmental statistics.

RESULTS:

Concomitant with the reduction of reported hepatitis A cases between 1992 and 1996 was a significant decline of HAV infections. The average prevalence decreased from 93.6% to 41.9%, and the average age at new infection was postponed from infancy to adolescence. This was attributed to improved socio-economic conditions. With intensive vaccination, a return of new seroconversion rate and seroprevalence was observed. A well fitted exponential regression equation (R(2)=0.96, p<0.0001) modeled that the maternal antibody would wane to <20 mIU/mL at 13 months.

CONCLUSION:

Benefiting from the booming economy, rapid improvement in sanitation, safe water supply, and implementation of hepatitis A vaccines, the epidemiological pattern of hepatitis A moved from high to intermediate endemicity in Shijiazhuang. Policy makers should be aware of the waning of immunity in entire population, and adapt immunization strategy timely, to ensure a lifelong protection against hepatitis A virus.

• Authors: Ying Chen, Xin-Jiang Zhang, Yu-Liang Zhao, Yan-Hong Zhang, Song-Mei Wang, Zhi-Yong Hao, Zhi-Yong Zhang, Jing-Chen Ma, Yun Fang, Xuan-Yi Wang
• Journal: Vaccine (Vaccine) Vol. 32 Issue 47 Pg. 6227-32 (Oct 29 2014) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 25258099 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.

Chemical References

• Hepatitis A Antibodies

Topics

• Adolescent
• Adult
• Aged
• Child
• Child, Preschool
• China (epidemiology)
• Cross-Sectional Studies
• Female
• Hepatitis A (epidemiology)
• Hepatitis A Antibodies (blood)
• Humans
• Immunity, Maternally-Acquired
• Male
• Middle Aged
• Prevalence
• Seroepidemiologic Studies
• Vaccination (statistics & numerical data)
• Young Adult