title: Performance and logistical challenges of alternative HIV-1 virological monitoring options in a clinical setting of Harare, Zimbabwe.
abstract: We evaluated a low-cost virological failure assay (VFA) on plasma and dried blood spot (DBS) specimens from HIV-1 infected patients attending an HIV clinic in Harare. The results were compared to the performance of the ultrasensitive heat-denatured p24 assay (p24). The COBAS AmpliPrep/COBAS TaqMan HIV-1 test, version 2.0, served as the gold standard. Using a cutoff of 5,000 copies/mL, the plasma VFA had a sensitivity of 94.5% and specificity of 92.7% and was largely superior to the VFA on DBS (sensitivity = 61.9%; specificity = 99.0%) or to the p24 (sensitivity = 54.3%; specificity = 82.3%) when tested on 302 HIV treated and untreated patients. However, among the 202 long-term ART-exposed patients, the sensitivity of the VFA decreased to 72.7% and to 35.7% using a threshold of 5,000 and 1,000 RNA copies/mL, respectively. We show that the VFA (either on plasma or on DBS) and the p24 are not reliable to monitor long-term treated, HIV-1 infected patients. Moreover, achieving acceptable assay sensitivity using DBS proved technically difficult in a less-experienced laboratory. Importantly, the high level of virological suppression (93%) indicated that quality care focused on treatment adherence limits virological failure even when PCR-based viral load monitoring is not available.
authors.affiliation: Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands.
authors.forename: Pascale
authors.identifier: 0000-0002-2700-9000
authors.initials: P
authors.lastname: Ondoa
authors.affiliation: Newlands Clinic, 56 Enterprise Road, Newlands, Harare, Zimbabwe.
authors.forename: Tinei
authors.identifier: 0000-0001-8931-4484
authors.initials: T
authors.lastname: Shamu
authors.affiliation: Department of Molecular Medicine and Haematology, University of the Witwatersrand 7 York Road, Parktown, Johannesburg 2193, South Africa.
authors.forename: Michelle
authors.initials: M
authors.lastname: Bronze
authors.affiliation: Newlands Clinic, 56 Enterprise Road, Newlands, Harare, Zimbabwe.
authors.forename: Maureen
authors.initials: M
authors.lastname: Wellington
authors.affiliation: Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands.
authors.forename: Tamara Sonia
authors.initials: TS
authors.lastname: Boender
authors.affiliation: Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands.
authors.forename: Corry
authors.initials: C
authors.lastname: Manting
authors.affiliation: Department of Molecular Medicine and Haematology, University of the Witwatersrand 7 York Road, Parktown, Johannesburg 2193, South Africa.
authors.forename: Kim
authors.initials: K
authors.lastname: Steegen
authors.affiliation: Newlands Clinic, 56 Enterprise Road, Newlands, Harare, Zimbabwe.
authors.forename: Rudi
authors.initials: R
authors.lastname: Luethy
authors.affiliation: Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands.
authors.forename: Tobias
authors.initials: T
authors.lastname: Rinke de Wit
mesh_terms: D059788:Dried Blood Spot Testing; D016655:HIV Core Protein p24 / Q000302:isolation & purification*; D015658:HIV Infections / Q000097:blood* / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D011933:Reagent Kits, Diagnostic; D013048:Specimen Handling; D019562:Viral Load; D014773:Virology / Q000379:methods*; D015030:Zimbabwe
chemical_list: D016655:HIV Core Protein p24; D011933:Reagent Kits, Diagnostic