title: Frequency of false positive rapid HIV serologic tests in African men and women receiving PrEP for HIV prevention: implications for programmatic roll-out of biomedical interventions.
abstract: BACKGROUND
  Rapid HIV assays are the mainstay of HIV testing globally. Delivery of effective biomedical HIV prevention strategies such as antiretroviral pre-exposure prophylaxis (PrEP) requires periodic HIV testing. Because rapid tests have high (>95%) but imperfect specificity, they are expected to generate some false positive results.
  
  
  METHODS
  We assessed the frequency of true and false positive rapid results in the Partners PrEP Study, a randomized, placebo-controlled trial of PrEP. HIV testing was performed monthly using 2 rapid tests done in parallel with HIV enzyme immunoassay (EIA) confirmation following all positive rapid tests.
  
  
  RESULTS
  A total of 99,009 monthly HIV tests were performed; 98,743 (99.7%) were dual-rapid HIV negative. Of the 266 visits with ≥1 positive rapid result, 99 (37.2%) had confirmatory positive EIA results (true positives), 155 (58.3%) had negative EIA results (false positives), and 12 (4.5%) had discordant EIA results. In the active PrEP arms, over two-thirds of visits with positive rapid test results were false positive results (69.2%, 110 of 159), although false positive results occurred at <1% (110/65,945) of total visits.
  
  
  CONCLUSIONS
  When HIV prevalence or incidence is low due to effective HIV prevention interventions, rapid HIV tests result in a high number of false relative to true positive results, although the absolute number of false results will be low. Program roll-out for effective interventions should plan for quality assurance of HIV testing, mechanisms for confirmatory HIV testing, and counseling strategies for persons with positive rapid test results.
authors.affiliation: Department of Global Health, University of Washington, Seattle, United States of America.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ndase
authors.affiliation: Department of Global Health, University of Washington, Seattle, United States of America; Department of Medicine, University of Washington, Seattle, United States of America; Department of Epidemiology, University of Washington, Seattle, United States of America.
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
authors.affiliation: Department of Global Health, University of Washington, Seattle, United States of America.
authors.forename: Lara
authors.initials: L
authors.lastname: Kidoguchi
authors.affiliation: Department of Medicine, University of Manitoba, Winnipeg, Canada; Infectious Disease Institute, Makerere University, Kampala, Uganda.
authors.forename: Allan
authors.initials: A
authors.lastname: Ronald
authors.affiliation: Department of Medicine, Indiana University, Indianapolis, United States of America.
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Fife
authors.affiliation: Department of Global Health, University of Washington, Seattle, United States of America; Department of Obstetrics and Gynecology, University of Nairobi and Kenyatta National Hospital, Nairobi, Kenya; Center for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya; Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, San Francisco, United States of America.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bukusi
authors.affiliation: Department of Global Health, University of Washington, Seattle, United States of America; Statistical Center for HIV/AIDS Research and Prevention, Fred Hutchinson Cancer Research Center, Seattle, United States of America.
authors.forename: Deborah
authors.initials: D
authors.lastname: Donnell
authors.affiliation: Department of Global Health, University of Washington, Seattle, United States of America; Department of Medicine, University of Washington, Seattle, United States of America; Department of Epidemiology, University of Washington, Seattle, United States of America.
authors.forename: Jared M
authors.initials: JM
authors.lastname: Baeten
mesh_terms: D000328:Adult; D005189:False Positive Reactions; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening; D065129:Pre-Exposure Prophylaxis; D015995:Prevalence