title: Epidemiology and clinical features of childhood chronic hepatitis B infection diagnosed in England.
abstract: BACKGROUND
  This study aimed to estimate the prevalence of childhood chronic hepatitis B (CHB) infection diagnosed in England using capture-recapture analysis of 2 independent data sources and to describe the clinical and epidemiological characteristics, management, complications and outcome of children with CHB.
  
  
  METHODS
  Pediatric specialists were contacted to report all CHB cases in children aged <16 years and complete a standardized questionnaire. Capture-recapture analysis of cases diagnosed during 2001-2009 using 2 independent data sources was performed to estimate the prevalence of childhood CHB.
  
  
  RESULTS
  Capture-recapture analysis estimated 448 diagnosed CHB cases (prevalence, 4.6/100,000) in England, of whom only 44% had been referred for specialist follow up. Clinical information for 325 cases under specialist care revealed that half the cases (n = 164, 50%) had been born overseas, mainly Sub-Saharan Africa and Eastern Europe, whereas half the UK-born children were either Pakistani (25%) or Chinese (25%). Most children (n = 216, 66%) were asymptomatic, with only 60 (18.5%) ever receiving any antiviral therapy, although 2 developed cirrhosis in childhood and 1 hepatocellular carcinoma. Horizontal transmission among UK-born children was identified in only 3 children born since 2001, when universal antenatal hepatitis B virus screening was introduced. Most children born to antenatally diagnosed hepatitis B virus-positive mothers (49/51, 96%) had received at least 1 hepatitis B vaccine dose after birth.
  
  
  CONCLUSIONS
  In England, the prevalence of diagnosed childhood CHB is low, although the potential number of undiagnosed cases is difficult to estimate. Further efforts are required to strengthen the current antenatal screening program and newly diagnosed cases should be referred for specialist follow up.
authors.affiliation: From the *Health Protection Agency; †King's College Hospital, Denmark Hill, London; ‡Leeds Teaching Hospitals NHS Trust, Leeds; §Barts and the London Children's Hospital, London; ¶Alder Hey Children's NHS Foundation Trust, Alder Hey Hospital, Liverpool; ‖Great Ormond Street Hospital; **Imperial College, London; and ††Birmingham Children's Hospital, Birmingham, UK.
authors.forename: Shamez N
authors.initials: SN
authors.lastname: Ladhani
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Flood
authors.forename: Gayatri
authors.initials: G
authors.lastname: Amirthalingam
authors.forename: Giorgina
authors.initials: G
authors.lastname: Mieli-Vergani
authors.forename: Sanjay
authors.initials: S
authors.lastname: Bansal
authors.forename: Suzanne
authors.initials: S
authors.lastname: Davison
authors.forename: Sandhia
authors.initials: S
authors.lastname: Naik
authors.forename: Andrew
authors.initials: A
authors.lastname: Riordan
authors.forename: Delane
authors.initials: D
authors.lastname: Shingadia
authors.forename: Gareth
authors.initials: G
authors.lastname: Tudor-Williams
authors.forename: Jaswant
authors.initials: J
authors.lastname: Sira
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: Kelly
authors.forename: Mary E
authors.initials: ME
authors.lastname: Ramsay
mesh_terms: D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D054242:Emigrants and Immigrants; D004739:England / Q000453:epidemiology; D005260:Female; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D012042:Registries