title: Failure of human immunodeficiency virus enzyme immunoassay to rule out infection among polymerase chain reaction-negative Vietnamese infants at 12 months of age.
abstract: BACKGROUND
  : Previous studies have demonstrated that >90% of HIV-uninfected infants serorevert, as seen in the results of enzyme immunoassay (EIA) testing by 12 months of age, making it feasible to confirm or rule out infection. We assessed the reliability of EIA in a cohort of Vietnamese infants.
  
  
  METHODS
  : HIV-exposed, uninfected infants enrolled in a parent diagnostic and monitoring study from February 2005 through August 2006 were eligible for inclusion in a prospective cohort study of HIV-EIA performance. Testing using 2 standard assays (Genscreen HIV 1/2 version 2, Bio-Rad; Murex 1.2.0, Murex Biotech) was initiated at 12 months of age. Infants were categorized as EIA-negative (seroreverted; negative Genscreen), EIA-indeterminate (positive Genscreen, negative Murex), or EIA-positive (Genscreen and Murex positive).
  
  
  RESULTS
  : Of 273 infants included in the study, 59 (22%) were EIA-negative at 12 months, 131 (48%) were indeterminate, and 83 (30%) were EIA-positive; specificity 21.6 (95% confidence interval: 16.6, 26.3). Infants with positive EIAs at 12 months were 74% more likely than EIA-indeterminate infants to test indeterminate or positive at 18 months (risk ratio, 1.74, 95% confidence interval: 1.15, 2.64; P = 0.03).
  
  
  CONCLUSIONS
  : Expectations regarding infant seroreversion by standard EIAs should be reassessed to reflect potential cross-regional differences in their performance.
authors.affiliation: Division of Pediatric Infectious Diseases, University of California, San Francisco, CA, USA. sohna@peds.ucsf.edu
authors.forename: Annette H
authors.initials: AH
authors.lastname: Sohn
authors.forename: Tran Chi
authors.initials: TC
authors.lastname: Thanh
authors.forename: Le Quoc
authors.initials: le Q
authors.lastname: Thinh
authors.forename: Truong Huu
authors.initials: TH
authors.lastname: Khanh
authors.forename: Huynh Khanh
authors.initials: HK
authors.lastname: Thu
authors.forename: Le Truong
authors.initials: le T
authors.lastname: Giang
authors.forename: Truong Xuan
authors.initials: TX
authors.lastname: Lien
mesh_terms: D015492:AIDS Serodiagnosis; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003951:Diagnostic Errors; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000276:immunology / Q000635:transmission / Q000821:virology; D018023:HIV Seronegativity; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D016015:Logistic Models; D008297:Male; D016133:Polymerase Chain Reaction; D014744:Vietnam