title: Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay.
abstract: OBJECTIVE
  We have evaluated the recently Conformité Européenne (CE)-marked Bio-Rad Geenius human immunodeficiency virus (HIV)1/2 as a rapid and simple alternative to western blot for confirmation of HIV screening results.
  
  
  METHODS
  A total of 160 serum samples were tested: 44 HIV-1 reactive samples by a fourth-generation Murex HIV Ag/Ab and/or Vidas HIV Duo Ultra, five HIV-2 reactive samples, 15 HIV-1 non-B subtype samples and 11 confirmed HIV-1 early seroconversion samples, 72 nonreactive samples, eight indeterminate samples by MP HIV BLOT 2.2 confirmed negative after follow-up and five low-reactive samples by enzyme immunoassay (EIA) negative by MP HIV BLOT 2.2. The samples were tested according to the manufacturer's guidelines.
  
  
  RESULTS
  The overall sensitivity for Bio-Rad Geenius HIV1/2 assay was 92%. Five out of 11 early seroconversion samples were tested positive, four negative and two indeterminate. All HIV-1 non-B subtype samples were tested positive. Two out of the five HIV-2 reactive samples were tested positive HIV-2, two positive HIV-2 with HIV-1 cross-reaction and one HIV positive untypable. After excluding early seroconversion samples, the sensitivity of Bio-Rad Geenius HIV1/2 assay reached 100%. Overall specificity was 96%. All HIV negative serums by fourth-generation EIA were tested negative. All five low-reactive samples by EIA, negative by HIV BLOT 2.2 were tested negative by Bio-Rad Geenius HIV1/2. Two out of the eight indeterminate samples by MP HIV BLOT 2.2 that were confirmed negative after follow-up were tested indeterminate and one invalid, the other five were negative. After excluding these last 13 samples, the specificity of Bio-Rad Geenius HIV1/2 assay reached 100%. In comparison with MP HIV BLOT 2.2, the Bio-Rad Geenius HIV1/2 assay was markedly time saving, allowed full traceability, automatic reading and interpretation.
  
  
  CONCLUSIONS
  The Bio-Rad Geenius HIV1/2 confirmatory system represents a reliable alternative to other confirmatory assays in HIV testing algorithms and provides clear improvement in quality management.
authors.affiliation: Microbiology Department, Erasmus Hospital, Route de Lennik 808, 1070 Brussels, Belgium. Electronic address: Carlota.Montesinos@erasme.ulb.ac.be.
authors.forename: Isabel
authors.initials: I
authors.lastname: Montesinos
authors.affiliation: Microbiology Department, Erasmus Hospital, Route de Lennik 808, 1070 Brussels, Belgium. Electronic address: Joelle.Eykmans@erasme.ulb.ac.be.
authors.forename: Joelle
authors.initials: J
authors.lastname: Eykmans
authors.affiliation: AIDS Reference Laboratory, Microbiology Department, Erasmus Hospital, Route de Lennik 808, 1070 Brussels, Belgium. Electronic address: Marie-Luce.Delforge@erasme.ulb.ac.be.
authors.forename: Marie-Luce
authors.initials: ML
authors.lastname: Delforge
mesh_terms: D015153:Blotting, Western / Q000379:methods; D015483:HIV Antibodies / Q000097:blood*; D015658:HIV Infections / Q000097:blood* / Q000175:diagnosis* / Q000821:virology; D006679:HIV Seropositivity; D015497:HIV-1 / Q000276:immunology*; D015498:HIV-2 / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D012698:Serologic Tests / Q000379:methods
chemical_list: D015483:HIV Antibodies
keywords: Geenius HIV1/2; HIV Western blot; HIV confirmatory tests