title: A single window-period donation detected by human immunodeficiency virus p24 antigen after 5 years of routine screening in a group of Brazilian blood banks.
abstract: OBJECTIVE
  The purpose of this article was to describe the experience of screening for human immunodeficiency virus (HIV) p24 antigen (p24Ag) in blood donors, in four Brazilian Blood Banks, and to report the detection of the first window-period donation.
  
  
  METHODS
  During 61 months (May 96 to June 01), 103 470 consecutive donations were screened for HIV p24Ag using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Testing was carried out in accordance with the instructions supplied with the kits.
  
  
  RESULTS
  Fifty-eight repeatedly reactive samples were identified [0.056% of the total; 95% confidence interval (95% CI): 0.042-0.070]. Ten of the 58 were confirmed as p24Ag positive after neutralization (0.010%; 95% CI: 0.004-0.016), nine of the 10 (0.009%; 95% CI: 0.003-0.014) were also HIV antibody positive and only one (0.001%; 95% CI: 0-0.003) was HIV antibody negative.
  
  
  CONCLUSIONS
  In this setting the rate of sole p24Ag-positive donations was one in 103 740. This figure corresponds closely with the previously estimated yield of one in 87 796 donations. The yield of HIV p24Ag+ : Ab- has been previously estimated in our centres to be 1 : 87 796 donations, a value similar to that observed in actual practice.
authors.affiliation: Blood Bank, Hospital Sírio Libanês, Rua Adma Jafet, São Paulo 01308-050, Brazil. snwendel@uninet.com.br
authors.forename: S
authors.initials: S
authors.lastname: Wendel
authors.forename: R M
authors.initials: RM
authors.lastname: Fachini
authors.forename: J E
authors.initials: JE
authors.lastname: Levi
authors.forename: J N
authors.initials: JN
authors.lastname: Ghaname
authors.forename: M C
authors.initials: MC
authors.lastname: Mendonça
authors.forename: C
authors.initials: C
authors.lastname: de Almeida Neto
authors.forename: M
authors.initials: M
authors.lastname: de Carvalho Braga
authors.forename: A E
authors.initials: AE
authors.lastname: Di Pietro
mesh_terms: D001771:Blood Banks; D001782:Blood Donors; D001938:Brazil; D004797:Enzyme-Linked Immunosorbent Assay; D016655:HIV Core Protein p24 / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D011237:Predictive Value of Tests; D012367:RNA, Viral / Q000097:blood; D014342:Truth Disclosure
chemical_list: D016655:HIV Core Protein p24; D012367:RNA, Viral