title: A pilot study for screening blood donors in Taiwan by nucleic acid amplification technology: detecting occult hepatitis B virus infections and closing the serologic window period for hepatitis C virus.
abstract: BACKGROUND
  Blood donors in Taiwan currently are screened for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection by immunoassay. The risk of enzyme immunoassay (EIA)-negative, nucleic acid amplification technology (NAT)-reactive donations is not well understood. This study aimed to screen for such donors in Taiwan by a multiplex test (cobas TaqScreen, Roche) on a commercially available NAT system (cobas s 201 system, Roche).
  
  
  METHODS
  NAT was performed on donors without prescreening in pools of six and NAT-reactive pools were then resolved to the single donation. Individual-donor NAT-reactive samples were discriminated by a commercially available polymerase chain reaction (PCR)-based diagnostic assay (COBAS AmpliScreen, Roche). Samples with EIA- and NAT-discordant results were investigated with supplemental serologic and confirmatory tests. Each sample taken from follow-up of HBV NAT yield cases was tested for HBV serologic profile, NAT, and viral load. The sensitivity and performance efficacy were also evaluated.
  
  
  RESULTS
  The 95 percent limit of detection (LOD) for HBV, HCV, and HIV were 5.09, 11.83, and 62.53 IU per mL, respectively. Among 10,727 seronegative donations, 12 HBV NAT yield cases (0.11%) and 1 HCV NAT yield case (0.01%) were detected. Follow-up results for 1 to 8 months showed that the HCV yield case was a window case and all HBV NAT yield cases were occult carriers.
  
  
  CONCLUSIONS
  The use of NAT detected occult HBV and reduced HCV window period. The yield rate, especially occult HBV, was 10- to 100-fold higher than that in developed, HBV nonendemic countries. Therefore, NAT implementation for routine donor screening in a more cost-effective manner should contribute to safer blood transfusion in Taiwan.
authors.affiliation: Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei, Taiwan.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Pei-Jer
authors.initials: PJ
authors.lastname: Chen
authors.forename: Ming-Hung
authors.initials: MH
authors.lastname: Chen
authors.forename: Kin-Fu
authors.initials: KF
authors.lastname: Chak
authors.forename: Kuo-Sin
authors.initials: KS
authors.lastname: Lin
authors.forename: Su-Jen Lin
authors.initials: SJ
authors.lastname: Tsai
mesh_terms: D015415:Biomarkers / Q000097:blood; D001782:Blood Donors; D004279:DNA, Viral / Q000235:genetics; D005500:Follow-Up Studies; D016174:Hepacivirus / Q000276:immunology*; D006509:Hepatitis B / Q000097:blood* / Q000175:diagnosis* / Q000635:transmission / Q000821:virology; D006526:Hepatitis C / Q000097:blood* / Q000175:diagnosis* / Q000635:transmission / Q000821:virology; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013624:Taiwan
chemical_list: D015415:Biomarkers; D004279:DNA, Viral