Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-2 (of 2 Records) |
Query Trace: Duong Pottinger Y[original query] |
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Field validation of limiting-antigen avidity enzyme immunoassay to estimate HIV-1 incidence in cross-sectional survey in Swaziland
Duong Pottinger Y , Dobbs T , Mavengere Y , Manjengwa J , Rottinghaus EK , Saito S , Bock N , Philip N , Justman J , Bicego G , Nkengasong JN , Parekh B . AIDS Res Hum Retroviruses 2019 35 (10) 896-905 Reliable and accurate laboratory assays to detect recent HIV-1 infection have potential as simple and practical methods of estimating HIV-1 incidence in cross-sectional surveys. This study describes validation of the limiting-antigen (LAg) Avidity enzyme immunoassay (EIA) in a cross-sectional national survey, conducted in Swaziland, comparing it to prospective follow up incidence. As part of the Swaziland HIV-1 Incidence Measurement Survey (SHIMS), 18,172 individuals underwent counselling and HIV rapid testing in a household-based, population survey conducted from December 2010 to June 2011. Plasma samples from HIV-positive persons were classified as recent infections using an incidence testing algorithm with LAg-Avidity EIA (ODn 1.5) followed by viral load (VL >/=1,000 copies/mL). All HIV-seronegative samples were tested for acute HIV-1 infection by nucleic acid amplification test (NAAT) pooling. HIV-seronegative individuals who consented to follow-up, were retested approximately 6 months later to detect observed HIV-1 seroconversion. HIV-1 incidence estimates based on LAg+VL and NAAT were calculated using assay-specific parameters and were compared with prospective incidence estimate. A total of 5,803 (31.9%) of 18,172 survey participants tested HIV-seropositive; of these 5683 (97.9%) were further tested with LAg+VL algorithm. The weighted annualized incidence from the longitudinal cohort study was 2.4% [95% CI 2.0, 2.7]. Based on cross-sectional testing of HIV-positives with LAg+VL algorithm, overall weighted annualized HIV-1 incidence was 2.5% [2.0, 3.0], while NAAT-based incidence was of 2.6%. In addition, LAg-based incidence in men (1.8%; 1.2-2.5) and women (3.2%; 2.4-3.9) were similar to estimates based on observed incidence (men=1.7%, women=3.1%). Changes in HIV-1 incidence with age in men and women further validate plausibility of the algorithm. These results demonstrate that the LAg EIA, in a serial algorithm with VL, is a cost-effective tool to estimate HIV-1 incidence in cross-sectional surveys. |
Evaluation of the performance of three biomarker assays for recent HIV infection using a well-characterized HIV-1 subtype C incidence cohort
Gonese E , Kilmarx P , van Schalkwyk C , Grebe E , Mutasa K , Ntozini R , Parekh B , Dobbs T , Duong Pottinger Y , Masciotra S , Owen M , Nachega J , van Zyl G , Hargrove J . AIDS Res Hum Retroviruses 2019 35 (7) 615-627 BACKGROUND: Biomarkers for detecting early HIV infection and estimating HIV incidence should minimise False-Recent Rates (FRRs) while maximising Mean Duration of Recent Infection (MDRIs). We compared BED capture enzyme immunoassay (BED), Sedia Limiting Antigen Avidity EIA (LAg) and Bio-Rad avidity incident incidence (BRAI) assays using samples from Zimbabwean postpartum women infected with clade C HIV. METHODS: We calculated MDRIs using 590 samples from 351 seroconverting postpartum women, and FRRs using samples from 2,825 women known to be HIV-positive for >12 months. RESULTS: Antibody kinetics were more predictable with LAg and had higher precision compared to BED or BRAI. BRAI also exhibited more variability, and avidity reversal in some cases. For BED, LAg and BRAI, used alone or with viral load (VL), MDRI values in days were: BED - 188 and 170 at normalized optical density (ODn) 0.8; LAg - 104 and 100 at ODn cut-off 1.5; BRAI - 135 and 134 at Avidity Index cut-off 30%. Corresponding FRRs were: BRAI 1.1% and 1.0% and LAg 0.57% and 0.35%: these were 3.8 - 10.9 times lower than BED values of 4.8% and 3.8 Conclusion: BRAI and LAg have significantly lower FRRs and MDRIs than in published studies, and much lower than BED and could be used to estimate incidence in perinatal women and to measure population level HIV incidence in HIV control operations in Africa. BRAI and LAg have significantly lower FRRs and MDRIs than in published studies, and much lower than BED. These improved methods could be used to estimate incidence in perinatal women and to measure population level HIV incidence in HIV control operations in Africa. |
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