Sustainable HIV treatment in Africa through viral-load-informed differentiated care

Abstract

There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy (ART) in sub-Saharan Africa. Patients typically attend clinics every 1–3 months for clinical assessment, with clinic costs being comparable with costs of drugs themselves, CD4 counts are measured every 6 months, yet patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes a transition to more cost-effective ART deliver is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (“viral load”) provides a direct measure of current treatment effect. Viral load informed differentiated care is a means of tailoring care whereby those with suppressed viral load have less frequent clinical visits and attention is paid to those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach in many countries to measure viral load is by collecting dried blood spot (DBS) samples for testing in regional laboratories, although there have been concerns over the sensitivity/specificity of DBS to define treatment failure and the delay in receiving results. We use modelling to synthesize available evidence and evaluate the cost-effectiveness of viral load-informed differentiated care, account for limitations of DBS. We find that viral load-informed differentiated care using DBS is expected to be cost-effective and is recommended as the strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of future availability of point-of-care (POC) viral load tests.

Evaluation of the Aptima HIV-1 Quant Dx Assay using plasma and dried blood spots

“…Using the WHO-recommended threshold of Ն1,000 copies/ml for therapy failure, we observed excellent agreement between DBS and EDTA plasma. These results, coupled with the simple Panther DBS work flow, suggest that DBS testing using Aptima is a promising option to meet the increased demand for virus load monitoring in lowresource settings necessitated by the global scale-up of ART (29,36). Furthermore, the specificity of TMA for RNA amplification may be of particular advantage for Aptima compared to RT-PCR methods for DBS virus load monitoring, given the confounding presence of proviral HIV-1 DNA in whole blood (37,38).…”

“…The DBS approach allows increased accessibility of virus load testing in remote, lowresource settings, as DBS are simple and inexpensive to both collect and transport (28). Moreover, modeling data suggest that virus load monitoring using DBS provides a mechanism for the cost-effective delivery of ART in low-resource settings (29). In this report, we describe the evaluation of Aptima and CAP/CTM for the quantitation of HIV-1 in plasma and DBS, with particular emphasis on the thresholds for clinical decision-making.…”

Evaluation of the Whole-Blood Alere Q NAT Point-of-Care RNA Assay for HIV-1 Viral Load Monitoring in a Primary Health Care Setting in Mozambique

“…HIV viral load testing at the POC may also extend test access to settings where conventional laboratory assays are not easily accessible (11,12). POC viral load tests may also facilitate the delivery of viral load-informed differentiated care for ART patients (13). Diagnostic testing at the POC improves test turnaround time, which may reduce the time to detection of treatment failure and the initiation of steps toward viral resuppression or therapy change (14)(15)(16)(17).…”

Point-of-Care Cepheid Xpert HIV-1 Viral Load Test in Rural African Communities Is Feasible and Reliable

“…Botswana has successfully initiated antiretroviral therapy in over 87% of the citizens living with HIV (1). The magnitude of this scale-up necessitates routine HIV-1 RNA testing for monitoring treatment failure and adherence (2)(3)(4)(5).…”