title: Seroepidemiology and risk factors of hepatitis B virus in Aden, Yemen.
abstract: BACKGROUND
  There is little published data concerning hepatitis B virus (HBV) infection in Aden and no data concerning risk factors for infection. This study aimed to determine the prevalence of HBV infection and risk factors for infection in Aden, Yemen.
  
  
  METHODS
  A prospective cross sectional survey of individuals attending primary health care facilities was stratified by age and population size. Five hundred and thirty five participants were interviewed and serum was screened for the presence of Immunoglobin G HBV core antibodies (antiHBc). AntiHBc positive participants were tested for antibodies to hepatitis B surface antigen (HBsAg). A case-control analysis of risk factors for HBV was undertaken comparing risk factors between antiHBc positive cases and seronegative controls.
  
  
  RESULTS
  The age-standardized seroprevalence for antiHBc was 16.2% (95% confidence interval (CI) 13.1-19.3) and for HBsAg was 1.5% (95% CI 0.5-2.5). The seroprevalence of antiHBc and HBsAg was estimated to range from 5.5% and 0% in infants to 40% and 4.6% in adults, respectively (p<0.001). Age (AOR=1.03, 95% CI=1.01-1.05), household size (>5-9 members, AOR=2.9, 95% CI=1.1-7.6) and ownership of a landline telephone (AOR=2.8, 95% CI=1.3-5.8) were independent risk factors for HBV infection.
  
  
  CONCLUSIONS
  HBV is still a public health problem in this community, with older individuals having much higher prevalence than younger generations. The results of this study would categorise Aden as a low HBV endemic zone. Perinatal transmission does not seem to be a major route of transmission.
authors.affiliation: Medical Faculty, Aden University, P.O. Box 6336, Khormaksar, Aden, Yemen. bawazir56@hotmail.com
authors.forename: Amen Ahmed
authors.initials: AA
authors.lastname: Bawazir
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Parry
authors.forename: C Anthony
authors.initials: CA
authors.lastname: Hart
authors.forename: Tallal A
authors.initials: TA
authors.lastname: Sallam
authors.forename: Nick
authors.initials: N
authors.lastname: Beeching
authors.forename: Luis E
authors.initials: LE
authors.lastname: Cuevas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D015006:Yemen / Q000453:epidemiology; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D007074:Immunoglobulin G