title: Hepatitis B in urban Australian schoolchildren. No evidence of horizontal transmission between high-risk and low-risk groups.
abstract: OBJECTIVE
  To document the prevalence of hepatitis B virus (HBV) infection in urban Australian primary schoolchildren, and to look for evidence of horizontal transmission of HBV in schools between children at high risk of infection and those at low risk. We compared the prevalence of infection in a group of low-risk children attending control schools (less than 5% of students from high-risk groups) with the prevalence in low-risk children attending test schools (more than 20% of students from high-risk groups).
  
  
  RESULTS
  Venous blood was collected and tested for hepatitis B markers by radioimmunoassay; 2883 children (1431 boys) of mean age 11.3 years (SD, 0.7) from 50 schools were tested. Evidence of past or current infection was present in 169 children (5.9%). This number comprised three of the 1347 low-risk children (0.2%), 10 of the 602 medium-risk children (1.7%), 154 of the 731 high-risk children (21.1%) and two of the 203 other children (1%). Fifty-four of the 169 infected children were hepatitis B surface antigen (HBsAg) positive, 36 of the 54 were also positive for hepatitis B e antigen (HBeAg). There was no difference between children in the low-risk group in test and control schools for markers of hepatitis B virus infection.
  
  
  CONCLUSIONS
  A low prevalence of HBV infection was found in low-risk school-children irrespective of the proportion of high-risk children in their classes. Targeting vaccination to infants and children with known risk factors is the most important strategy in low endemicity countries; vaccination of children without risk factors could be delayed till early adolescence.
authors.affiliation: Children's Hospital, Camperdown, NSW.
authors.forename: M A
authors.initials: MA
authors.lastname: Burgess
authors.forename: E D
authors.initials: ED
authors.lastname: McIntosh
authors.forename: H M
authors.initials: HM
authors.lastname: Allars
authors.forename: K G
authors.initials: KG
authors.lastname: Kenrick
mesh_terms: D001208:Asia / Q000208:ethnology; D002648:Child; D005006:Ethnicity; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control / Q000635:transmission*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines; D006513:Hepatitis B e Antigens / Q000097:blood; D006801:Humans; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D014505:Urban Population; D014611:Vaccination
chemical_list: D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D006513:Hepatitis B e Antigens