title: Relative sensitivities of licensed nucleic acid amplification tests for detection of viremia in early human immunodeficiency virus and hepatitis C virus infection.
abstract: BACKGROUND
  Screening donors for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) RNA is primarily performed on minipools (MPs) with one of two commercial nucleic acid amplification tests (NAT; Roche Molecular Systems; or Gen-Probe/Chiron). We compared these assays with respect to detection of RNA in early HIV and HCV infection.
  
  
  METHODS
  Twelve HIV plasma donor panels (116 serial samples) and 12 HCV panels (180 serial samples) were selected to optimally represent early viremia. Initial testing was performed in singlicate or triplicate on separately coded aliquots, both neat and at dilutions corresponding to MP screening (1:16 for Gen-Probe; 1:24 for Roche); 20 additional replicates were performed when discordant results were observed. Odds ratios (ORs) comparing detection of RNA by different assays were derived with logistic regression models. Differences in window-period closure and yields of assays in MP or individual-donation (ID) format were estimated.
  
  
  RESULTS
  Differences in detection rates between Roche and Gen-Probe NAT assays were small and only observed with samples with very-low-level viremia. ORs for detecting RNA by the Gen-Probe versus the Roche assay were significant for HIV if conducted on MPs (1.8; 95% confidence interval [CI], 1.3-2.5) but not neat (1.0; 95% CI, 0.72-1.4). Odds of detecting HCV RNA were higher if the Gen-Probe assay was conducted either neat (2.3; 95% CI, 1.6-3.2) or on MPs (4.0; 95% CI, 2.8-5.8). These differences translated to <1 day window-period closure and <or=1 infection per 20 million donations. In contrast, comparisons of ID versus MP assays were highly significant for both viruses (ORs for ID vs. MP ranged from 45.3 to 93.4), with projected yields of one to two additional infections per 10 million donations.
  
  
  CONCLUSIONS
  Differences in sensitivities of licensed NAT assays for HIV and HCV are very small and clinically insignificant, particularly when compared to differences of MP versus ID NAT screening.
authors.affiliation: Blood Systems Research Institute, San Francisco, California 94118, USA. mpbusch@itsa.ucsf.edu
authors.forename: Michael P
authors.initials: MP
authors.lastname: Busch
authors.forename: Simone A
authors.initials: SA
authors.lastname: Glynn
authors.forename: David J
authors.initials: DJ
authors.lastname: Wright
authors.forename: Dale
authors.initials: D
authors.lastname: Hirschkorn
authors.forename: Megan E
authors.initials: ME
authors.lastname: Laycock
authors.forename: Joan
authors.initials: J
authors.lastname: McAuley
authors.forename: Yongling
authors.initials: Y
authors.lastname: Tu
authors.forename: Cristina
authors.initials: C
authors.lastname: Giachetti
authors.forename: James
authors.initials: J
authors.lastname: Gallarda
authors.forename: John
authors.initials: J
authors.lastname: Heitman
authors.forename: Steven H
authors.initials: SH
authors.lastname: Kleinman
mesh_terms: D000094902:Blood Banking / Q000379:methods; D006678:HIV / Q000235:genetics* / Q000302:isolation & purification; D015658:HIV Infections / Q000097:blood / Q000175:diagnosis*; D016174:Hepacivirus / Q000235:genetics* / Q000302:isolation & purification; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008004:Licensure; D008403:Mass Screening / Q000379:methods; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012367:RNA, Viral / Q000097:blood / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D014766:Viremia / Q000097:blood / Q000175:diagnosis
chemical_list: D012367:RNA, Viral