title: Pooled nucleic acid testing increases the diagnostic yield of acute HIV infections in a high-risk population compared to 3rd and 4th generation HIV enzyme immunoassays.
abstract: OBJECTIVE
  We compared a 3rd generation (gen) and two 4th gen HIV enzyme immunoassays (EIA) to pooled nucleic acid testing (PNAT) for the identification of pre- and early seroconversion acute HIV infection (AHI).
  
  
  METHODS
  9550 specimens from males >18 year from clinics attended by men who have sex with men were tested by Siemens ADVIA Centaur(®) HIV 1/O/2 (3rd gen) and HIV Combo (4th gen), as well as by Abbott ARCHITECT(®) HIV Ag/Ab Combo (4th gen). Third gen non-reactive specimens were also tested by Roche COBAS(®) Ampliprep/COBAS® TaqMan HIV-1 Test v.2 in pools of 24 samples. Sensitivity and specificity of the three EIAs for AHI detection were compared.
  
  
  RESULTS
  7348 persons contributed 9435 specimens and had no evidence of HIV infection, 79 (94 specimens) had established HIV infection, 6 (9 specimens) had pre-seroconversion AHI and 9 (12 specimens) had early seroconversion AHI. Pre-seroconversion AHI cases were not detected by 3rd gen EIA, whereas 2/6 (33.3%) were detected by Siemens 4th gen, 4/6 (66.7%) by Abbott 4th gen and 6/6 (100%) by PNAT. All three EIAs and PNAT detected all individuals with early seroconversion AHI. Overall sensitivity/specificity for the EIAs relative to WB or NAT resolved infection status was 93.6%/99.9% for Siemens 3rd gen, 95.7%/99.7% for Siemens 4th gen and 97.9%/99.2% for Abbott 4th gen.
  
  
  CONCLUSIONS
  While both 4th gen EIAs demonstrated improved sensitivity for AHI compared to 3rd gen EIA, PNAT identified more AHI cases than either 4th gen assay. PNAT is likely to remain a useful strategy to identify AHI in high-risk populations.
authors.affiliation: Clinical Prevention Services, BC Centre for Disease Control, 655 West 12th Ave, Vancouver, BC V5Z 4R4, Canada; Faculty of Medicine, University of British Columbia, 2194 Health Sciences Mall, Vancouver, BC V6 T 1Z3, Canada; Public Health Microbiology & Reference Laboratory, BC Centre for Disease Control, 655 West 12th Ave Vancouver, BC V5Z 4R4, Canada. Electronic address: mel.krajden@bccdc.ca.
authors.forename: Mel
authors.initials: M
authors.lastname: Krajden
authors.affiliation: Clinical Prevention Services, BC Centre for Disease Control, 655 West 12th Ave, Vancouver, BC V5Z 4R4, Canada.
authors.forename: Darrel
authors.initials: D
authors.lastname: Cook
authors.affiliation: Public Health Microbiology & Reference Laboratory, BC Centre for Disease Control, 655 West 12th Ave Vancouver, BC V5Z 4R4, Canada.
authors.forename: Annie
authors.initials: A
authors.lastname: Mak
authors.affiliation: Public Health Microbiology & Reference Laboratory, BC Centre for Disease Control, 655 West 12th Ave Vancouver, BC V5Z 4R4, Canada.
authors.forename: Ken
authors.initials: K
authors.lastname: Chu
authors.affiliation: Public Health Microbiology & Reference Laboratory, BC Centre for Disease Control, 655 West 12th Ave Vancouver, BC V5Z 4R4, Canada.
authors.forename: Navdeep
authors.initials: N
authors.lastname: Chahil
authors.affiliation: Clinical Prevention Services, BC Centre for Disease Control, 655 West 12th Ave, Vancouver, BC V5Z 4R4, Canada; Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Steinberg
authors.affiliation: Faculty of Medicine, University of British Columbia, 2194 Health Sciences Mall, Vancouver, BC V6 T 1Z3, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Rekart
authors.affiliation: Clinical Prevention Services, BC Centre for Disease Control, 655 West 12th Ave, Vancouver, BC V5Z 4R4, Canada; Faculty of Medicine, University of British Columbia, 2194 Health Sciences Mall, Vancouver, BC V6 T 1Z3, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Gilbert
mesh_terms: D000328:Adult; D000368:Aged; D006678:HIV / Q000235:genetics*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009696:Nucleic Acids / Q000032:analysis*; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D009696:Nucleic Acids
keywords: 4th generation EIA; Acute HIV; HIV diagnostics; Pooled nucleic acid testing