title: [Seroprevalence study of hepatitis B among orienteers].
abstract: 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Programa de Epidemiología Aplicada de Campo, Instituto de Salud Carlos III, Madrid, España. vhernando@isciii.es
authors.forename: Victoria
authors.initials: V
authors.lastname: Hernando
authors.forename: Pilar
authors.initials: P
authors.lastname: Soler
authors.forename: Ramón
authors.initials: R
authors.lastname: Pedro
authors.forename: Luis
authors.initials: L
authors.lastname: García
authors.forename: Jesús
authors.initials: J
authors.lastname: Castilla
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: García
authors.forename: Carmen
authors.initials: C
authors.lastname: Quiñones
authors.forename: Visitación
authors.initials: V
authors.lastname: García
authors.forename: Virtudes
authors.initials: V
authors.lastname: Gallardo
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Echevarria
authors.forename: Rosendo
authors.initials: R
authors.lastname: Jardi
authors.forename: María José
authors.initials: MJ
authors.lastname: Bleda
authors.forename: Salvador
authors.initials: S
authors.lastname: De Mateo
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D005260:Female; D006509:Hepatitis B / Q000097:blood* / Q000453:epidemiology*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000276:immunology; D006801:Humans; D008297:Male; D016036:Seroepidemiologic Studies; D013030:Spain / Q000453:epidemiology; D013177:Sports; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens