Mayorga Perez, Orlando; Brinkhof, Martin W G; Egger, Matthias; Frösner, Gert; Herzog, Christian; Zwahlen, Marcel (2014). Decreasing risk of hepatitis a infection in león, nicaragua: evidence from cross-sectional and longitudinal seroepidemiology studies. PLoS ONE, 9(2), e87643. Public Library of Science 10.1371/journal.pone.0087643
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BACKGROUND AND OBJECTIVES
Nicaragua is highly endemic for hepatitis A. We aimed to provide an estimate of the change in the age-specific risk of hepatitis A virus (HAV) infection based on serological data from cross-sectional and longitudinal samples collected in León, Nicaragua, in 1995/96 (n = 979) and 2003 (n = 494).
METHODS
The observed age-specific prevalence of anti-HAV antibodies was correlated to the age-specific risk of infection by calculating the probability of freedom from infection at a specific age.
RESULTS
The proportion of seropositive children aged 1.5 to 6 years was 42% in 2003 compared to 67% in 1995/96. Estimated annual risk of infection for a 3-year old child was 30% (95% CI: 27.0%, 33.1%) in 1995 and 15.5% (95% CI: 12.4%, 19.0%) in 2003. There was good agreement between estimates based on cross-sectional and longitudinal data. The age-specific geometric mean of the quantified anti-HAV antibody levels assessed in 2003 was highest at age 4 and decreased steadily up to age 40.
CONCLUSIONS
The substantially lower risk of HAV infection in 2003 than in 1995 for young children indicates a beginning transition from high to intermediate endemicity in León, Nicaragua. Consecutive age-stratified serosurveys are useful to assess changes in risk of infection following public health interventions. The decreasing age-specific GMC of anti-HAV antibodies during adulthood in a country with endemic HAV indirectly suggests that ongoing HAV exposure in the community has marginal boosting effect on antibody levels once protective immunity has been established by natural infection.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Social and Preventive Medicine (ISPM) |
UniBE Contributor: |
Brinkhof, Martin, Egger, Matthias, Herzog, Christian, Zwahlen, Marcel |
Subjects: |
600 Technology > 610 Medicine & health 300 Social sciences, sociology & anthropology > 360 Social problems & social services |
ISSN: |
1932-6203 |
Publisher: |
Public Library of Science |
Language: |
English |
Submitter: |
Beatrice Minder Wyssmann |
Date Deposited: |
19 Mar 2014 17:25 |
Last Modified: |
05 Dec 2022 14:28 |
Publisher DOI: |
10.1371/journal.pone.0087643 |
PubMed ID: |
24523871 |
BORIS DOI: |
10.7892/boris.41802 |
URI: |
https://boris.unibe.ch/id/eprint/41802 |
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