title: Estimations of worldwide prevalence of chronic hepatitis B virus infection: a systematic review of data published between 1965 and 2013.
abstract: BACKGROUND
  The quantification of the burden of disease attributable to hepatitis B virus (HBV) infection and the adaptation of prevention and control measures requires knowledge on its prevalence in the general population. For most countries such data are not routinely available. We estimated the national, regional, and global prevalence of chronic HBV infection.
  
  
  METHODS
  For this systematic review and pooled analysis, we searched for data on prevalence of chronic HBV infection published between Jan 1, 1965, and Oct 23, 2013, in the databases Medline, Embase, CAB Abstracts (Global health), Popline, and Web of Science. We included studies reporting the hepatitis B surface antigen (HBsAg) serological marker of chronic HBV infection in non-high-risk groups and extracted data into a customised database. For each country, we calculated HBsAg prevalence estimates and 95% CIs weighted by study size. We extrapolated prevalence estimates to population sizes in 2010 to obtain the number of individuals with chronic HBV infection.
  
  
  RESULTS
  Of the 17,029 records screened, 1800 report on the prevalence of HBsAg covering 161 countries were included. HBsAg seroprevalence was 3·61% (95% CI 3·61-3·61) worldwide with highest endemicity in countries of the African region (total 8·83%, 8·82-8·83) and Western Pacific region (total 5·26%, 5·26-5·26). Within WHO regions, prevalence ranged from 0·20% (0·19-0·21; Mexico) to 13·55% (9·00-19·89; Haiti) in the Americas, to 0·48% (0·12-1·90; the Seychelles) to 22·38% (20·10-24·83; South Sudan) in the African region. We estimated that in 2010, globally, about 248 million individuals were HBsAg positive.
  
  
  CONCLUSIONS
  This first global assessment of country-level population prevalence of chronic HBV infection found a wide variation between countries and highlights the need for continued prevention and control strategies and the collection of reliable epidemiologic data using standardised methodology.
  
  
  BACKGROUND
  World Health Organization.
authors.affiliation: Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany; PhD Programme 'Epidemiology' Braunschweig-Hannover, Braunschweig, Germany.
authors.forename: Aparna
authors.initials: A
authors.lastname: Schweitzer
authors.affiliation: Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany; PhD Programme 'Epidemiology' Braunschweig-Hannover, Braunschweig, Germany; Research Group Epidemiological and Statistical Methods, Helmholtz Center for Infection Research, Braunschweig, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Horn
authors.affiliation: Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Research Group Epidemiological and Statistical Methods, Helmholtz Center for Infection Research, Braunschweig, Germany; Hannover Medical School, Hannover, Germany.
authors.forename: Rafael T
authors.initials: RT
authors.lastname: Mikolajczyk
authors.affiliation: Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Hannover Medical School, Hannover, Germany.
authors.forename: Gérard
authors.initials: G
authors.lastname: Krause
authors.affiliation: Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Hannover Medical School, Hannover, Germany. Electronic address: Joerdis.Ott@helmholtz-hzi.de.
authors.forename: Jördis J
authors.initials: JJ
authors.lastname: Ott
mesh_terms: D014943:Global Health / Q000706:statistics & numerical data*; D019694:Hepatitis B, Chronic / Q000453:epidemiology*; D006801:Humans; D015995:Prevalence; D012307:Risk Factors