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

Abstract

Viral load testing is the WHO-recommended monitoring assay for patients on HIV antiretroviral therapy (ART). Point-of-care(POC) assays may help improve access to viral load testing in resource-limited settings. We compared the performance of the Alere Q NAT POC viral load technology (Alere Technologies, Jena, Germany), measuring total HIV RNA using finger prick capillary whole-blood samples collected in a periurban health center, with that of a laboratory-based plasma RNA test (Roche Cobas Ampliprep/Cobas TaqMan v2) conducted on matched venous blood samples. The whole-blood Alere Q NAT POC assay produced results with a bias of 0.8593 log copy/ml compared to the laboratory-based plasma assay. However, at above 10,000 copies/ ml, the bias was 0.07 log copy/ml. Using the WHO-recommended threshold to determine ART failure of 1,000 copies/ml, the sensitivity and specificity of the whole-blood Alere Q NAT POC assay were 96.83% and 47.80%, respectively. A cutoff of 10,000 copies/ml of whole blood with the Alere Q NAT POC assay appears to be a better predictor of ART failure threshold (1,000 copies/ml of plasma), with a sensitivity of 84.0% and specificity of 90.3%. The precision of the whole-blood Alere Q NAT POC assay was comparable to that observed with the laboratory technology (5.4% versus 7.5%) between detectable paired samples. HIV POC viral load testing is feasible at the primary health care level. Further research on the value of whole-blood viral load to monitor antiretroviral therapy is warranted. The World Health Organization strongly recommends the use of viral load testing as the primary tool for HIV antiretroviral treatment (ART) monitoring in its 2015 consolidated ART guidelines (1). The Joint United Nations Programme on HIV/AIDS (UNAIDS) has also highlighted the importance of viral load testing in its new 90-90-90 HIV targets and has launched a global initiative to increase access to viral load and other HIV diagnostic tests (2, 3). However, many resource-limited countries face challenges in implementing HIV viral load testing within their public health programs due to limited laboratory infrastructure, capacity, and skills. Emerging point-of-care (POC) technologies offer the opportunity to decentralize diagnostic testing and greatly expand access to quality health care (4).Plasma-based RNA constitutes the conventional gold standard specimen type and biomarker for HIV viral load measurement. Currently, however, plasma-based testing requires venipuncture and processing of blood specimens using centrifugation to separate plasma, which require some laboratory infrastructure. The use of finger or heel prick capillary blood samples increases the ease of use of POC tests and enables both sample collection and viral load testing to be decentralized to locations that lack laboratories, required infrastructure, or skilled technicians.The use of whole blood, although operationally advantageous, presents a technical problem, since both intracellular and extracellular RNA and DNA are present in the specimen and mig...

Challenges of HIV diagnosis and management in the context of pre‐exposure prophylaxis (PrEP), post‐exposure prophylaxis (PEP), test and start and acute HIV infection: a scoping review

“…The re‐formulated Alere TM HIV Combo has shown much improved sensitivity for detection of p24 antigen , however, further evaluation of its use in clinical practice is required. Other options include diagnostic platforms for RNA testing, such as the Alere™ q HIV‐1/2 Detect which has been validated for RNA detection among infants and children, the Cepheid GeneXpert ® , the technology for which already has an existing presence in sub‐Saharan Africa where it is predominantly used for tuberculosis testing , and SAMBA which is a dipstick‐based nucleic acid assay for the detection of HIV in whole blood developed for monitoring and diagnostic use in LMIC settings.…”

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

“…Despite the development of several POC viral load technologies over the last decade (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24), there is a shortage of commercially available tests. In this study, we evaluated the performance of the POC Cepheid Xpert HIV-1 viral load test in rural communities in Botswana in order to provide additional data to policy makers regarding the use of this assay in decentralized HIV treatment programs.…”

Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening

“…Current sample preparation usually involves lengthy or error-prone manual processes such as gravity-driven filtration (Lucchi et al, 2016), centrifugation (Sema et al, 2015). Although a few emerging point of care NAT devices, such as Alere q system (Hsiao et al, 2016; Jani et al, 2016), cobas Liat system (Nolte et al, 2016) and Cepheid Xpert Omni platform (Gous et al, 2016), have successfully integrated the sample preparation step, a low-cost LAMP-based malaria NATs is not readily available for screening test. While centrifuge-based lab-on-a-disc (Kim et al, 2014; Kong et al, 2016; Madou et al, 2006; Nolte, 2009) is a promising technology to integrate DNA extraction on the chip, centrifugal force is non-linear in nature and energy-hungry thanks to the rotational frequencies in the range of several thousand revolutions per minute (RPM) (Madou et al, 2006).…”