Point-of-Care HIV Viral Load Testing: an Essential Tool for a Sustainable Global HIV/AIDS Response

Abstract

The global public health community has set ambitious treatment targets to end the HIV/AIDS pandemic. With the notable absence of a cure, the goal of HIV treatment is to achieve sustained suppression of an HIV viral load, which allows for immunological recovery and reduces the risk of onward HIV transmission. Monitoring HIV viral load in people living with HIV is therefore central to maintaining effective individual antiretroviral therapy as well as monitoring progress toward achieving population targets for viral suppression. The capacity for laboratory-based HIV viral load testing has increased rapidly in low- and middle-income countries, but implementation of universal viral load monitoring is still hindered by several barriers and delays. New devices for point-of-care HIV viral load testing may be used near patients to improve HIV management by reducing the turnaround time for clinical test results. The implementation of near-patient testing using these new and emerging technologies may be an essential tool for ensuring a sustainable response that will ultimately enable an end to the HIV/AIDS pandemic. In this report, we review the current and emerging technology, the evidence for decentralized viral load monitoring by non-laboratory health care workers, and the additional considerations for expanding point-of-care HIV viral load testing.

Keywords: AIDS; HIV; differentiated care; point-of-care; viral load.

FIG 1

Point-of-care HIV viral load equipment and test cartridges currently marketed (A to F) or in development (G to K). Attendant key equipment for some devices, such as modems, barcode scanners, or printers, is not included. (A) The Abbott m-PIMA analyzer; (B) the Abbott m-PIMA HIV-1/2 test cartridge; (C) the Cepheid GX4 instrument; (D) the Cepheid Xpert HIV-1 viral load test cartridge; (E) the DRW SAMBA II test module with controller; (F) the DRW SAMBA II plasma semiquantitative test; (G) the Cepheid Omni instrument and controller; (H) the Molbio Diagnostics Trueprep sample preparation device; (I to K) the Molbio Diagnostics Truelab amplification instruments in Uno (I), Duo (J), and Quattro (K) module formats. (Images are reprinted with permission of the respective manufacturers.)

FIG 2

Examples of various steps which must be integrated into potential POC HIV viral load tests. (A) Sample collection should be simple to perform and provide precise volume metering. (B) Membrane-based plasma separation to exclude proviral HIV DNA in PBMCs. (C) Viral lysis using a detergent to denature the viral envelope and release HIV RNA. (D) Magnetic bead-based RNA extraction to purify RNA from blood-related inhibitors and lytic agents. (E) Amplification of nucleic acids to detectable concentrations. (F) Algorithm and device to provide quantitative results and communicate results to electronic health records (EHR).

FIG 3

The building blocks of differentiated ART delivery with POC HIV viral load testing. OI, opportunistic infection. (Adapted from reference with permission.)

FIG 4

A conceptual model of integrated point-of-care testing within differentiated care.