Painless Capillary Blood Collection: A Rapid Evaluation of the Onflow Device.

Blood-based diagnostics are critical for many medical decisions, but mostly rely on venepuncture, which can be inconvenient and painful. The Onflow Serum Gel (Loop Medical SA, Vaud, Lausanne, Switzerland) is a novel blood collection device that utilises needle-free technology to collect capillary blood. In this pilot study, 100 healthy participants were enrolled and provided two Onflow collected specimens and one venous blood specimen. Five chemistry analytes (AST, ALT, LDH, potassium, creatinine) and haemolysis were measured per specimen, and laboratory analyte results were compared. Onflow was found to be more acceptable than venepuncture with lower pain ratings, and 96.5% of participants would use the Onflow method again. All phlebotomists (100%) found Onflow intuitive and user-friendly, with ~1 mL of Onflow blood successfully collected from 99% of participants in <12 min (mean: 6 min, 40 s) and 91% collected on the first attempt. ALT and AST analytes showed no difference in performance, while creatinine generated a negative bias (-5.6 µmol/L), and increased variability was noted with potassium (3.6%CV) and LDH (6.7%CV), although none were clinically relevant. These differences may be due to 35% of Onflow collected specimens having "mild" haemolysis. Onflow is a promising alternative blood collection device that should now be evaluated in participants with expected abnormal chemistries and as an option for self-collection.

Performance Evaluation of Four Qualitative RT-PCR Assays for the Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019, and its rapid spread around the globe led the World Health Organization to declare it a pandemic. Laboratory diagnostics provide important information to help control virus transmission, and molecular nucleic acid amplification tests have been recognized as the gold standard for the direct detection of viral genetic material. The main aim of this study was to independently evaluate the analytical performance of four molecular assays that were designed for the detection of SARS-CoV-2 on open testing platforms under emergency use approval, namely, the COVIWOK COVID-19 RT-PCR Meril COVID-19 One-step RT-PCR Kit, the AmoyDx Novel Coronavirus (2019-nCoV) Detection Kit, the Meril COVID-19 One-step RT-PCR Kit and the NeoPlex COVID-19 Detection Kit, as alternatives to the current standard of care (SOC) assays in-country. All of the evaluated assays showed an acceptable performance, with a specificity of 100% and a sensitivity of 93.8% to 98.4%, compared to a SOC assay, with a Cohen's kappa coefficient of ≥0.9 (95% CI). In addition, the assays detected the AccuPlex reference material at 100 copies/mL, suggesting a good limit of detection. These assays provide suitable alternatives to the SOC assays that are currently available in-country, and these alternatives are acceptable for diagnostic use in South Africa. IMPORTANCE Laboratory diagnosis plays an important role in curbing the transmission of infection and reducing harmful delays in clinical and public health responses. Alternatives to the current standard of care assays for SARS-CoV-2 are important in order to overcome the challenges that are associated with global demands and supply shortages. Four molecular assays for the detection of SARS-CoV-2 that were designed for open testing platforms were evaluated in this study under emergency use approval. These assays had acceptable performance and provide suitable alternatives to the current standard of care assays that are available in-country. Their compatibilities with existing in-country amplification platforms make these assays convenient to use for diagnostic testing, both locally and globally These assays were recommended to the South African Health Products Regulatory Authority (SAHPRA) for patient care in South Africa.

Rapid Evaluation of the Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus Tests.

The Xpert® Xpress SARS-CoV-2 and Xpert® Xpress SARS-CoV-2/Flu/RSV tests were rapidly developed and widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In response to emerging genetic variability, a new SARS-CoV-2 target (RNA-dependent RNA-polymerase) has been added to both tests: Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus test. A rapid evaluation of both tests was performed in South Africa, using residual respiratory specimens. Residual respiratory specimens (n = 125) were used to evaluate the Xpert® Xpress CoV-2 plus test and included 50 genotyped specimens. The Xpert® Xpress CoV-2/Flu/RSV plus test was assessed using 45 genotyped SARS-CoV-2 specimens, 10 influenza A, 10 influenza B and 20 respiratory syncytial virus specimens. Results were compared to in-country standard-of-care tests. Genotyped specimens tested the performance of the test under pressure from circulating SARS-CoV-2 variants of concern. Reference material was included to assess the test limits and linearity. The Xpert® Xpress CoV-2 plus test performance compared to reference results across residual respiratory specimens was good (positive percentage agreement (PPA) = 95.2%, negative percentage agreement (NPA) = 95.0%) The Xpert® Xpress CoV-2/Flu/RSV plus test showed good performance across all residual respiratory specimens (PPA = 100%, NPA = 98.3%). All genotyped variants of concern were detected by both tests. The Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus tests can be used to diagnose SARS-CoV-2, and to diagnose and differentiate SARS-CoV-2, influenza A, influenza B and respiratory syncytial virus, respectively. The NPA was lower than the recommended 99%, but was influenced by the low number of negative specimens tested. The variants of concern assessed did not affect test performance. It is recommended that sites perform their own assessments compared to in-country standard-of-care tests.

The Development of a Standardized Quality Assessment Material to Support Xpert® HIV-1 Viral Load Testing for ART Monitoring in South Africa.

The tiered laboratory framework for human immunodeficiency virus (HIV) viral load monitoring accommodates a range of HIV viral load testing platforms, with quality assessment critical to ensure quality patient testing. HIV plasma viral load testing is challenged by the instability of viral RNA. An approach using an RNA stabilizing buffer is described for the Xpert® HIV-1 Viral Load (Cepheid) assay and was tested in remote laboratories in South Africa. Plasma panels with known HIV viral titres were prepared in PrimeStore molecular transport medium for per-module verification and per-instrument external quality assessment. The panels were transported at ambient temperatures to 13 testing laboratories during 2017 and 2018, tested according to standard procedures and uploaded to a web portal for analysis. A total of 275 quality assessment specimens (57 verification panels and two EQA cycles) were tested. All participating laboratories met study verification criteria (n = 171 specimens) with an overall concordance correlation coefficient (ρc) of 0.997 (95% confidence interval (CI): 0.996 to 0.998) and a mean bias of -0.019 log copies per milliliter (cp/mL) (95% CI: -0.044 to 0.063). The overall EQA ρc (n = 104 specimens) was 0.999 (95% CI: 0.998 to 0.999), with a mean bias of 0.03 log cp/mL (95% CI: 0.02 to 0.05). These panels are suitable for use in quality monitoring of Xpert® HIV-1 VL and are applicable to laboratories in remote settings.