The measurement of HIV-1 viral load in resource-limited settings: how and where?
ABSTRACT There is an urgent need for low-cost, simple, and accurate human immunodeficiency virus type 1 (HIV-1) viral load monitoring technologies in resource-limited settings, particularly at the time of the scaling-up of first and second-line highly active antiretroviral therapies. This review describes the main characteristics and advantages/ disadvantages of three alternative HIV-1 viral load methods currently evaluated and used in developing countries, i.e., the Ultra p24 antigen assay, the ExaVir Load reverse transcriptase activity test, and 'home-made' real-time PCR HIV-1 RNA techniques. This review discusses clinical results obtained with these three technologies in terms of correlation with commercial HIV-1 RNA assays, the impact of HIV-1 genetic diversity on quantification, as well as their usefulness for both the early diagnosis of pediatric HIV-1 infection and monitoring of highly active antiretroviral therapy efficiency. In addition, different strategies for HIV-1 viral load monitoring are discussed according to laboratory facilities in resource-constrained settings.
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ABSTRACT: In low resource -countries like Benin, HIV viral load is rarely available for monitoring antiretroviral treatment, which is generally based in these settings on clinical assessment together with T-cell CD4 count. In this study, we present our experience of setting up HIV viral load in Cotonou and the relative contribution of this test in monitoring such patients. From May 2013 to January 2014, 139 participants aged above 15 years were tested for both T-cell CD4 count and HIV viral load. We observed that HIV viral load was above 3 Log 10 copies/ml in 15 participants (10.8%) though their CD4 count was above 350 cells/µl. HIV viral load could help for early detection of patients with incomplete virologic response to antiretroviral treatment in Cotonou. Copyright © 2014 Dissou Affolabi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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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.BioMed Research International 06/2014; 2014(Article ID 102598). DOI:10.1155/2014/102598 · 2.71 Impact Factor