title: The significance of transfusion in the past as a risk for current hepatitis B and hepatitis C infection: a study in endoscopy patients.
abstract: BACKGROUND
  The objective was to determine the contribution of transfusion in the past to the risk of current infection with hepatitis B or C among patients attending a large hospital for endoscopic procedures.
  
  
  METHODS
  Blood samples had been tested for hepatitis markers by routine methods. Patients completed a comprehensive risk factor questionnaire and results were analyzed using computer software.
  
  
  RESULTS
  Twenty-seven percent of the 2120 participants in the study received transfusions in the past. There was no increase in prevalence of hepatitis B among those transfused. Compared with nontransfused participants, recipients of blood before the implementation of hepatitis C virus (HCV) screening in 1990 had a 4.6-fold increased risk of HCV infection, whereas those transfused with screened blood had a 3-fold increased risk. The difference between the odds ratios for patients before and after screening was not significant.
  
  
  CONCLUSIONS
  Because screening has almost completely eliminated HCV from the blood supply, our finding of a continuing association of HCV infection with transfusion was unexpected. It implies that there are significant other nosocomial risks for hepatitis C transmission associated with the clinical situations where patients received blood. These should be actively investigated.
authors.affiliation: Department of Infectious Diseases and Immunology, University of Sydney, Sydney, Australia.
authors.forename: Hani M
authors.initials: HM
authors.lastname: Tawk
authors.forename: Karen
authors.initials: K
authors.lastname: Vickery
authors.forename: Linda
authors.initials: L
authors.lastname: Bisset
authors.forename: Sing Kai
authors.initials: SK
authors.lastname: Lo
authors.forename: Yvonne E
authors.initials: YE
authors.lastname: Cossart
mesh_terms: D000328:Adult; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D004724:Endoscopy / Q000706:statistics & numerical data*; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000635:transmission; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D015999:Multivariate Analysis; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors