School of Computer Science and Applied Mathematics

Permanent URI for this community

https://wiredspace.wits.ac.za/handle/10539/20394
For queries regarding content of Faculty of Science please contact Salome Potgieter by email : salome.potgieter@wits.ac.za or Tel : 011 717 1961

Browse

Browsing School of Computer Science and Applied Mathematics by Author "Dobbs, T."

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Recalibration of the limiting antigen avidity EIA to determine mean duration of recent infection in divergent HIV-1 subtypes.
    (Public Library of Science, 2015-02-24) Duong, Y.T.; Kassanjee, R.; Welte, A.; Ampofo, W.; Parekh, B.S.; Morgan, M.; De, A.; Dobbs, T.; Rottinghaus, E.; Nkengasong, J.; Curlin, M.E.; Kittinunvorakoon, C.; Raengsakulrach, B.; Martin, M.; Choopanya, K.; Vanichseni, S.; Jiang, Y.; Qiu, M.; Yu, H.; Hao, Y.; Shah, N.; Le, L.-V.; Kim, A.A.; Nguyen, T.A.
    Background: Mean duration of recent infection (MDRI) and misclassification of long-term HIV-1 infections, as proportion false recent (PFR), are critical parameters for laboratory-based assays for estimating HIV-1 incidence. Recent review of the data by us and others indicated that MDRI of LAg-Avidity EIA estimated previously required recalibration. We present here results of recalibration efforts using >250 seroconversion panels and multiple statistical methods to ensure accuracy and consensus. Methods: A total of 2737 longitudinal specimens collected from 259 seroconverting individuals infected with diverse HIV-1 subtypes were tested with the LAg-Avidity EIA as previously described. Data were analyzed for determination of MDRI at ODn cutoffs of 1.0 to 2.0 using 7 statistical approaches and sub-analyzed by HIV-1 subtypes. In addition, 3740 specimens from individuals with infection >1 year, including 488 from patients with AIDS, were tested for PFR at varying cutoffs. Results: Using different statistical methods,MDRI values ranged from 88-94 days at cutoff ODn = 1.0 to 177-183 days at ODn = 2.0. The MDRI values were similar by different methods suggesting coherence of different approaches. Testing formisclassification among long-terminfections indicated that overall PFRs were 0.6%to 2.5%at increasing cutoffs of 1.0 to 2.0, respectively. Balancing the need for a longer MDRI and smaller PFR (<2.0%) suggests that a cutoff ODn = 1.5, corresponding to an MDRI of 130 days should be used for cross-sectional application. The MDRI varied among subtypes from 109 days (subtype A&D) to 152 days (subtype C). Conclusions: Based on the new data and revised analysis, we recommend an ODn cutoff = 1.5 to classify recent and long-term infections, corresponding to an MDRI of 130 days (118-142). Determination of revised parameters for estimation of HIV-1 incidence should facilitate application of the LAg-Avidity EIA for worldwide use.