title: Declining hepatitis C rates in first-time blood donors: insight from surveillance and case-control risk factor studies.
abstract: BACKGROUND
  Hepatitis C virus (HCV) rates have decreased steadily in first-time donors in Canada since testing was implemented but reasons are unclear. A description of factors that may have played a role in this decline is reported.
  
  
  METHODS
  Descriptive analysis of first-time blood donors by HCV positivity status and year (1993--2006), sex, and age was carried out. HCV-positive first-time donors and matched controls participated in a confidential scripted telephone interview about risk factors in 1993 through 1994 and in 2005 through 2006, and risk factors independently predicting HCV positivity were determined with multiple logistic regression.
  
  
  RESULTS
  HCV-positive donations occurred most frequently in donors born between 1945 and 1964 and decreased in this birth cohort over time (p < 0.01). At present, most first-time donors (74%) are born after 1964. History of intravenous drug use, sex with an intravenous drug user, blood transfusion, and tattoo independently predicted (p < 0.01) HCV positivity in both periods (1993--1994 and 2005--2006).
  
  
  CONCLUSIONS
  Most HCV-positive donors were born between 1945 and 1964, and the decline in HCV rates is associated primarily with this birth cohort. The key risk factors predicting HCV positivity did not change over the 13 years of the study. With approximately two-thirds of HCV-positive Canadians in the general population having been tested for HCV, potential donors may be aware of their HCV status and be likely to self-defer. This, and an increasing proportion of first-time donors born after 1964, may contribute to declining HCV rates in first-time donors.
authors.affiliation: National Epidemiology and Surveillance, Canadian Blood Services, Ottawa, Ontario, Canada. sheila.o'brien@blood.ca
authors.forename: Sheila F
authors.initials: SF
authors.lastname: O'Brien
authors.forename: Wenli
authors.initials: W
authors.lastname: Fan
authors.forename: Guoliang
authors.initials: G
authors.lastname: Xi
authors.forename: Qi-Long
authors.initials: QL
authors.lastname: Yi
authors.forename: Mindy
authors.initials: M
authors.lastname: Goldman
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Fearon
authors.forename: Claire
authors.initials: C
authors.lastname: Infante-Rivard
authors.forename: Jo Anne
authors.initials: JA
authors.lastname: Chiavetta
authors.forename: Bernard
authors.initials: B
authors.lastname: Willems
authors.forename: David
authors.initials: D
authors.lastname: Pi
authors.forename: Margaret
authors.initials: M
authors.lastname: Fast
authors.forename: Gilles
authors.initials: G
authors.lastname: Delage
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001782:Blood Donors / Q000706:statistics & numerical data*; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006266:Health Education; D006526:Hepatitis C / Q000097:blood* / Q000453:epidemiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors