title: Detection of acute infections during HIV testing in North Carolina.
abstract: BACKGROUND
  North Carolina has added nucleic acid amplification testing for the human immunodeficiency virus (HIV) to standard HIV antibody tests to detect persons with acute HIV infection who are viremic but antibody-negative.
  
  
  METHODS
  To determine the effect of nucleic acid amplification testing on the yield and accuracy of HIV detection in public health practice, we conducted a 12-month observational study of methods for state-funded HIV testing. We compared the diagnostic performance of standard HIV antibody tests (i.e., enzyme immunoassay and Western blot analysis) with an algorithm whereby serum samples that yielded negative results on standard antibody tests were tested again with the use of nucleic acid amplification. A surveillance algorithm with repeated sensitive-less-sensitive enzyme immunoassay tests was also evaluated. HIV infection was defined as a confirmed positive result on a nucleic acid amplification test or as HIV antibody seroconversion.
  
  
  RESULTS
  Between November 1, 2002, and October 31, 2003, 109,250 persons at risk for HIV infection who had consented to HIV testing presented at state-funded sites. There were 606 HIV-positive results. Established infection, as identified by standard enzyme immunoassay or Western blot analysis, appeared in 583 participants; of these, 107 were identified, with the use of sensitive-less-sensitive enzyme immunoassay tests, as recent infections. A total of 23 acutely infected persons were identified only with the use of the nucleic acid amplification algorithm. With all detectable infections taken into account, the sensitivity of standard antibody testing was 0.962 (95 percent confidence interval, 0.944 to 0.976). There were two false positive results on nucleic acid amplification tests. The specificity and positive predictive value of the algorithm that included nucleic acid amplification testing were greater than 0.999 (95 percent confidence interval, 0.999 to >0.999) and 0.997 (95 percent confidence interval, 0.988 to >0.999), respectively. Of the 23 acute HIV infections, 16 were detected at sexually transmitted disease clinics. Emergency measures for HIV prevention protected 48 sex partners and one fetus from high-risk exposure to HIV.
  
  
  CONCLUSIONS
  The addition of nucleic acid amplification testing to an HIV testing algorithm significantly increases the identification of cases of infection without impairing the performance of diagnostic testing. The detection of highly contagious, acutely infected persons creates new opportunities for HIV surveillance and prevention.
authors.affiliation: Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, USA. cpilcher@med.unc.edu
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Pilcher
authors.forename: Susan A
authors.initials: SA
authors.lastname: Fiscus
authors.forename: Trang Q
authors.initials: TQ
authors.lastname: Nguyen
authors.forename: Evelyn
authors.initials: E
authors.lastname: Foust
authors.forename: Leslie
authors.initials: L
authors.lastname: Wolf
authors.forename: Del
authors.initials: D
authors.lastname: Williams
authors.forename: Rhonda
authors.initials: R
authors.lastname: Ashby
authors.forename: Judy Owen
authors.initials: JO
authors.lastname: O'Dowd
authors.forename: J Todd
authors.initials: JT
authors.lastname: McPherson
authors.forename: Brandt
authors.initials: B
authors.lastname: Stalzer
authors.forename: Lisa
authors.initials: L
authors.lastname: Hightow
authors.forename: William C
authors.initials: WC
authors.lastname: Miller
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Eron
authors.forename: Myron S
authors.initials: MS
authors.lastname: Cohen
authors.forename: Peter A
authors.initials: PA
authors.lastname: Leone
mesh_terms: D000208:Acute Disease; D000328:Adult; D000465:Algorithms; D015153:Blotting, Western; D016358:Contact Tracing; D003365:Costs and Cost Analysis; D005260:Female; D015483:HIV Antibodies / Q000097:blood; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000635:transmission; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques; D015994:Incidence; D008297:Male; D009657:North Carolina / Q000453:epidemiology; D021141:Nucleic Acid Amplification Techniques / Q000191:economics; D012367:RNA, Viral / Q000097:blood
chemical_list: D015483:HIV Antibodies; D012367:RNA, Viral