Applicability of SAMBA point-of care devices in real-world settings

Abstract

In this thesis I present the need for and applications of point-of care devices in the real-world settings. There are currently limited nucleic acid tests (NAT) based on point-of-care (POC) platforms that are appropriately adapted to resource constrained settings. Centralised testing algorithms lead to poor access to testing, long turnaround times, high loss to follow up and delayed results. Suitable POC testing platforms developed for this environment will allow these much-needed NAT’s to be decentralised, bringing them closer to the patient. Such platforms must be suitable for POC settings in smaller healthcare facilities as well as the developing world. POC testing is required to be easy to use, inexpensive and with robust equipment and stable reagents. The Simple AMplification Based Assay (SAMBA) system has been developed specifically for the POC, with easy visual detection of the result and simple instrumentation, in addition to robust reagents that are stable at high temperatures. Pre-dispensed reagents in single use, sealed disposable cartridges that prevent amplicon contamination, make them easy to handle for the operator. This reduces time to result, time to treatment initiation and increases savings due to wastage and lost samples. The work presented in this thesis highlights the importance of the following: Importance of point of care devices and their rollout and implementation in decentralised remote settings with limited availability of resources. Four SAMBA assays have been evaluated and the results have been summarised in this thesis.

SAMBA HIV-1 Semi Q Test using plasma for monitoring of HIV-1 infected patients (Chapter 2) SAMBA HIV-1 Qual Whole Blood Assay for early infant diagnosis (Chapter 3) SAMBA HIV-1 Semi-Q Whole Blood Assay for monitoring of HIV-1 infected patients (Chapter 4) SAMBA SARS-COV-2 Assay for COVID-19 diagnosis (Chapter 5)

In addition, task shifting studies performed on the SAMBA POC system demonstrated that all levels of healthcare workers can run the assay proficiently and upon completion of the training protocol provide training to peers. Healthcare levels participating in the study ranged from laboratory technologists, laboratory assistants, nurses, midwives, microscopists, nursing assistants and counsellors from two countries (Chapter 3). COVID-19 testing and roll out of the SAMBA II POC diagnostic test in the pandemic setting also demonstrated the advantages of POC platforms as it enabled the hospital settings to test and quarantine patients prior to admission. This impacted the transmission rates within the hospitals and protected the patients and the staff from exposure from infected individuals. Using POC tools to detect novel infections with accuracy in a short timeframe is therefore critical in both developed and developing worlds. Overall, this thesis summarises the clinical assessment and performances of the SAMBA assays for HIV-1 and COVID-19 detection and implementation in patient care pathways. All assays showed promising performance and could potentially contribute to the improvement of disease management in real world settings.