title: Incidence rates of viral infections among repeat donors:are frequent donors safer?
abstract: BACKGROUND
  Incidence rates (IRs) for viral infections may vary with the frequency of donation among repeat, community, whole-blood (WB) donors, with IRs thought to be lower among donors with higher frequency of donation.
  
  
  METHODS
  IRs for HIV, HTLV, HCV, and HBV infection were stratified by frequency of donation among 868,403 repeat WB donors who gave approximately 4 million donations at five United States blood centers from 1991 through 96. All donors had given at least 2 donations during those years, with the first donation being nonreactive on confirmatory testing. Frequency of donation was measured in three ways: by the number of donations per year; at the time of donation, by the number of donations given within the preceding 2-year period; and by the number of donations given from 1991 through 1993.
  
  
  RESULTS
  The IRs for HIV, HCV, and HBV infection did not appear to differ among donors with lower or higher numbers of donation per year. However, the IR for HTLV infection decreased as the number of donations per year increased (p = 0.0004). IRs for all viral markers remained stable, regardless of the number of donations given within the 2-year period before the donation. Although IRs for HIV, HTLV, and HCV infection did not vary by the number of donations given in 1991 through 1993, the IR for HBV infection appeared to be lower in donors who gave more donations in that period (p = 0.01).
  
  
  CONCLUSIONS
  These findings do not provide evidence of a lower IR for transfusion-transmissible viral infections among repeat WB donors who give more frequently. Abbreviated screening histories for frequent repeat donors might not be advisable.
authors.affiliation: Westat, Rockville, Maryland 20850, USA. schreigl@westat.com
authors.forename: G B
authors.initials: GB
authors.lastname: Schreiber
authors.forename: S A
authors.initials: SA
authors.lastname: Glynn
authors.forename: M P
authors.initials: MP
authors.lastname: Busch
authors.forename: U K
authors.initials: UK
authors.lastname: Sharma
authors.forename: D J
authors.initials: DJ
authors.lastname: Wright
authors.forename: S H
authors.initials: SH
authors.lastname: Kleinman
mesh_terms: D000328:Adult; D001782:Blood Donors; D001800:Blood Specimen Collection / Q000009:adverse effects / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D014777:Virus Diseases / Q000635:transmission*