Publication: Evaluation of a sensitive/less-sensitive testing algorithm using the 3A11-LS assay for detecting recent HIV seroconversion among individuals with HIV-1 subtype B or E infection in Thailand
Issued Date
2001-04-02
Resource Type
ISSN
08892229
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2-s2.0-0035794280
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Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
AIDS Research and Human Retroviruses. Vol.17, No.5 (2001), 453-458
Suggested Citation
B. S. Parekh, D. J. Hu, S. Vanichseni, G. A. Satten, D. Candal, N. L. Young, D. Kitayaporn, L. O. Srisuwanvilai, S. Rakhtam, R. Janssen, K. Choopanya, T. D. Mastro Evaluation of a sensitive/less-sensitive testing algorithm using the 3A11-LS assay for detecting recent HIV seroconversion among individuals with HIV-1 subtype B or E infection in Thailand. AIDS Research and Human Retroviruses. Vol.17, No.5 (2001), 453-458. doi:10.1089/088922201750102562 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/26569
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Title
Evaluation of a sensitive/less-sensitive testing algorithm using the 3A11-LS assay for detecting recent HIV seroconversion among individuals with HIV-1 subtype B or E infection in Thailand
Abstract
The development of a serologic algorithm to determine recent HIV seroconversion, using sensitive/less-sensitive testing strategies, has generated widespread interest in applying this approach to estimate HIV-1 incidence in various populations around the world. To evaluate this approach in non-B subtypes, longitudinal specimens (n = 522) collected from 90 incident infections among injecting drug users in Bangkok (subtype B infection, n = 18; subtype E infection, n = 72) were tested by the 3A11-LS assay. Standardized optical density (SOD) was calculated, using median values, and the window period between seroconversion as determined by sensitive and less sensitive tests was estimated by a maximum-likelihood model described previously. Our results show that the mean window period of the 3A11-LS assay was 155 days (95% CI, 128-189 days) for subtype B but was 270 days (95% CI, 187-349 days) for subtype E specimens from Thailand. About 4% of individuals with incident subtype E infections remained below the threshold (SOD of 0.75), even 2 years after seroconversion. Among the patients with clinical AIDS and declining antibodies, none of the 7 individuals with subtype B, but 10 (8.7%) of 115 with subtype E infections, were misclassified as recent infections. Lowering the cutoff to an SOD of 0.45 for subtype E specimens resulted in a mean window period of 185 days (95% CI, 154-211 days), with all individuals seroconverting, and reduced the number of subtype E-infected patients with AIDS who were misclassified as having recent infection to 2.6%. Our results demonstrate that the 3A11-LS assay has different performance characteristics in detecting recent infections among individuals infected with subtypes B or E. Determining appropriate cutoffs and mean window periods for other HIV-1 subtypes will be necessary before this approach can be reliably implemented in settings where non-B subtypes are common.