title: Hepatitis B and residual risk of infection in English and Welsh blood donors, 1996 through 2008.
abstract: BACKGROUND
  Globally, of all infections that donations are tested for, hepatitis B has the highest residual risk of transfusion transmission, despite donor selection criteria and advances in testing. Every blood donation in England and Wales is tested for hepatitis B surface antigen. Knowledge of infections being detected can inform donor selection and testing strategies.
  
  
  METHODS
  Data on donation testing and infections detected are collated by the NHS Blood and Transplant and Health Protection Agency Epidemiology Unit. Infected donors are classified as having acute or chronic hepatitis B virus (HBV) by a clinician; their demographic characteristics were described. The prevalence (by acute or chronic HBV status, ethnicity, and geography) and incidence of infection were calculated between 1996 and 2008. The residual risk was calculated for four periods using a modification of the incidence and window period model; the effects of modifying variables were investigated.
  
  
  RESULTS
  Most infections (1047/1155) detected were chronic and seen in new donors. People with acute infections were more likely to be white and/or born in Western Europe. Prevalence was highest in donors from minority ethnic communities and in London. Incidence in repeat donors has halved in recent years. The estimated frequency of an infectious donation being missed was 1.37 per million donations (2006-2008), the lowest since surveillance began or three per year.
  
  
  CONCLUSIONS
  Many HBV infections in England and Wales were detected among new donors, who had chronic infection and were born overseas. The residual risk of infection declined over the 13 study years, but is still higher for HBV than other viral infections for which testing is undertaken.
authors.affiliation: Health Protection Agency Centre for Infections and NHS Blood and Transplant, London, UK.
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Brant
authors.forename: Claire
authors.initials: C
authors.lastname: Reynolds
authors.forename: Lisa
authors.initials: L
authors.lastname: Byrne
authors.forename: Katy L
authors.initials: KL
authors.lastname: Davison
mesh_terms: D001782:Blood Donors / Q000706:statistics & numerical data*; D001803:Blood Transfusion / Q000706:statistics & numerical data; D054242:Emigrants and Immigrants; D004739:England; D005006:Ethnicity; D006509:Hepatitis B / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D015994:Incidence; D007239:Infections / Q000453:epidemiology / Q000635:transmission; D015995:Prevalence; D012306:Risk; D065227:Transfusion Reaction; D014852:Wales