Related Experiment Video
Updated: Jun 23, 2026

Dried Blood Spots - Preparing and Processing for Use in Immunoassays and in Molecular Techniques
Published on: March 13, 2015
[Seroprevalence study of hepatitis B among orienteers]
Victoria Hernando1, Pilar Soler, Ramón Pedro
1Programa de Epidemiología Aplicada de Campo, Instituto de Salud Carlos III, Madrid, España. vhernando@isciii.es
Background And Objective:
Our objectives were to detect asymptomatic cases involved in an outbreak of hepatitis B, to assess the seroprevalence of hepatitis B (HB) in orienteers and to establish recommendations.
Patients And Method:
One hundred sixteen orienteers who had competed in the categories involved in the previous outbreak as well as a stratified random sample of 166 of the remaining orienteers in other competition categories were included in a cross-sectional serological prevalence study. HB surface antigen (anti-HBs); total antibody to HB core antigen (total anti-HBc); HB surface antigen (Ag HBs); and antibody IgM to HB core antigen (anti-HBcIgM) along with the history of vaccination for hepatitis B were analyzed. The results were weighted.
Results:
The seroprevalence of HB (total anti-HBc positive) was 6.7% (n=12, 95% CI 0.6-12.9). No case of acute HB or chronic infection was observed. All the serological markers were negative for 61.1% (n=64, 95% CI 46.3-75.6), and 31.5% (n=29, 95% CI 18.2-46.4) had markers of immunity due to vaccination. Among individuals under 25 years of age, 28.4% were unvaccinated, although they were covered by vaccination programs.
Conclusion:
Our results suggest that the seroprevalence of HB among orienteers is not different from the general population in Spain. However, it is necessary to reinforce the vaccination among adolescents and young adults. General recommendations for the prevention of HB were made to orienteering federations.
Related Concept Videos
Hepatitis
Viral Hepatitis I: Introduction
Infectious Diseases and Their Occurrence
Investigation of Disease Outbreaks
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health condition at a...
Bias in Epidemiological Studies
