title: Refinement of a viral transmission risk model for blood donations in seroconversion window phase screened by nucleic acid testing in different pool sizes and repeat test algorithms.
abstract: BACKGROUND
  In minipool nucleic acid test (MP-NAT) screening protocols, the donations implicated in reactive test pools are released for transfusion when they are nonreactive in a repeat test on the individual samples, but in individual-donation (ID)-NAT screening algorithms the release of nonrepeatable reactive (NRR) donations is under discussion.
  
  
  METHODS
  A previously developed window phase (WP) transmission risk model for NAT-screened blood transfusions has been refined to take the effect of repeat tests of initially reactive (IR) MP- or ID-NAT results into account. The model has then been applied to simulate the effect of different screening algorithms with ULTRIO and the new-generation ULTRIO Plus assay (Novartis Diagnostics) on transmission risk for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV).
  
  
  RESULTS
  We calculated WP risk-day equivalents for MP16-, MP8-, and ID-NAT with and without duplicate retesting of IR results of 3.1, 2.7, 1.5, and 1.3 days for HCV; 6.3, 5.5, 3.3, and 2.9 days for HIV; and 24.4, 22.2, 15.6, and 14.1 days for HBV, respectively. These latter infectious HBV WPs reduced to 20.4, 18.2, 11.6, and 10.3 days, respectively, with the more sensitive ULTRIO Plus assay.
  
  
  CONCLUSIONS
  ULTRIO Plus ID-NAT screening reduces the virus transmission risk in the WP by 54% to 58% compared to ULTRIO MP16-NAT, while the incremental risk caused by releasing donations with duplicate ID-NAT NRR results is 5% to 6%. To achieve maximum safety and specificity a similar repeat test algorithm can be applied to ID-NAT as used for serologic assays.
authors: bioMérieux, Boxtel, the Netherlands.
authors: Jos
authors: J
authors: Weusten
authors: Marion
authors: M
authors: Vermeulen
authors: Harry
authors: H
authors: van Drimmelen
authors: Nico
authors: N
authors: Lelie
mesh_terms: D000465:Algorithms; D001782:Blood Donors / Q000706:statistics & numerical data; D004279:DNA, Viral / Q000235:genetics; D015658:HIV Infections / Q000635:transmission / Q000821:virology; D006509:Hepatitis B / Q000635:transmission / Q000821:virology; D006526:Hepatitis C / Q000635:transmission / Q000821:virology; D006801:Humans; D008962:Models, Theoretical; D012367:RNA, Viral / Q000235:genetics; D065227:Transfusion Reaction
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral