title: Estimating False-Recent Classification for the Limiting-Antigen Avidity EIA and BED-Capture Enzyme Immunoassay in Vietnam: Implications for HIV-1 Incidence Estimates.
abstract: Laboratory tests that can distinguish recent from long-term HIV infection are used to estimate HIV incidence in a population, but can potentially misclassify a proportion of long-term HIV infections as recent. Correct application of an assay requires determination of the proportion false recents (PFRs) as part of the assay characterization and for calculating HIV incidence in a local population using a HIV incidence assay. From April 2009 to December 2010, blood specimens were collected from HIV-infected individuals attending nine outpatient clinics (OPCs) in Vietnam (four from northern and five from southern Vietnam). Participants were living with HIV for ≥1 year and reported no antiretroviral (ARV) drug treatment. Basic demographic data and clinical information were collected. Specimens were tested with the BED capture enzyme immunoassay (BED-CEIA) and the Limiting-antigen (LAg)-Avidity EIA. PFR was estimated by dividing the number of specimens classified as recent by the total number of specimens; 95% confidence intervals (CI) were calculated. Specimens that tested recent had viral load testing performed. Among 1,813 specimens (north, n = 942 and south, n = 871), the LAg-Avidity EIA PFR was 1.7% (CI: 1.2-2.4) and differed by region [north 2.7% (CI: 1.8-3.9) versus south 0.7% (CI: 0.3-1.5); p = .002]. The BED-CEIA PFR was 2.3% (CI: 1.7-3.0) and varied by region [north 3.4% (CI: 2.4-4.7) versus south 1.0% (CI: 0.5-1.2), p < .001]. Excluding specimens with an undetectable VL, the LAg-Avidity EIA PFR was 1.2% (CI: 0.8-1.9) and the BED-CEIA PFR was 1.7% (CI: 1.2-2.4). The LAg-Avidity EIA PFR was lower than the BED-CEIA PFR. After excluding specimens with an undetectable VL, the PFR for both assays was similar. A low PFR should facilitate the implementation of the LAg-Avidity EIA for cross-sectional incidence estimates in Vietnam.
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Neha S
authors.initials: NS
authors.lastname: Shah
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Yen T
authors.initials: YT
authors.lastname: Duong
authors.affiliation: 2 Centers for Disease Control and Prevention , Hanoi, Vietnam .
authors.forename: Linh-Vi
authors.initials: LV
authors.lastname: Le
authors.affiliation: 3 National Institute of Hygiene and Epidemiology , Hanoi, Vietnam .
authors.forename: Nguyen Anh
authors.initials: NA
authors.lastname: Tuan
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Bharat S
authors.initials: BS
authors.lastname: Parekh
authors.affiliation: 3 National Institute of Hygiene and Epidemiology , Hanoi, Vietnam .
authors.forename: Hoang Thi Thanh
authors.initials: HTT
authors.lastname: Ha
authors.affiliation: 4 Ho Chi Minh City Pasteur Institute , Ho Chi Minh City, Vietnam .
authors.forename: Quang Duy
authors.initials: QD
authors.lastname: Pham
authors.affiliation: 4 Ho Chi Minh City Pasteur Institute , Ho Chi Minh City, Vietnam .
authors.forename: Cao Thi Thu
authors.initials: CTT
authors.lastname: Cuc
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Trudy
authors.initials: T
authors.lastname: Dobbs
authors.affiliation: 3 National Institute of Hygiene and Epidemiology , Hanoi, Vietnam .
authors.forename: Tran Hong
authors.initials: TH
authors.lastname: Tram
authors.affiliation: 4 Ho Chi Minh City Pasteur Institute , Ho Chi Minh City, Vietnam .
authors.forename: Truong Thi Xuan
authors.initials: TTX
authors.lastname: Lien
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Nick
authors.initials: N
authors.lastname: Wagar
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Chunfu
authors.initials: C
authors.lastname: Yang
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Amy
authors.initials: A
authors.lastname: Martin
authors.affiliation: 2 Centers for Disease Control and Prevention , Hanoi, Vietnam .
authors.forename: Mitchell
authors.initials: M
authors.lastname: Wolfe
authors.affiliation: 3 National Institute of Hygiene and Epidemiology , Hanoi, Vietnam .
authors.forename: Nguyen Tran
authors.initials: NT
authors.lastname: Hien
authors.affiliation: 1 Centers for Disease Control and Prevention , Atlanta, Georgia .
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003951:Diagnostic Errors; D004812:Epidemiologic Methods; D015488:HIV Antigens / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D015994:Incidence; D008875:Middle Aged; D012698:Serologic Tests / Q000379:methods*; D014744:Vietnam / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015488:HIV Antigens
keywords: HIV; epidemiology; incidence; prevention