Implementing COVID-19 (SARS-CoV-2) Rapid Diagnostic Tests in Sub-Saharan Africa: A Review

Abstract

Introduction: For the COVID-19 (SARS-CoV-2) response, COVID-19 antigen (Ag), and antibody (Ab) rapid diagnostic tests (RDTs) are expected to complement central molecular testing particularly in low-resource settings. The present review assesses requirements for implementation of COVID-19 RDTs in sub-Saharan Africa. Methods:Review of PubMed-published articles assessing COVID-19 RDTs complemented with Instructions for Use (IFU) of products.Results: In total 47 articles on two COVID-19 Ag RDTs and 54 COVID-19 Ab RDTs and IFUs of 20 COVID-19 Ab RDTs were retrieved. Only five COVID-19 Ab RDTs (9.3%) were assessed with capillary blood sampling at the point-of-care; none of the studies were conducted in sub-Saharan Africa. Sampling: Challenges for COVID-19 Ag RDTs include nasopharyngeal sampling (technique, biosafety) and sample stability; for COVID-19 Ab RDTs equivalence of whole blood vs. plasma/serum needs further validation (assessed for only eight (14.8%) products). Sensitivity-Specificity: sensitivity of COVID-19 Ag and Ab RDTs depend on viral load (antigen) and timeframe (antibody), respectively; COVID-19 Ab tests have lower sensitivity compared to laboratory test platforms and the kinetics of IgM and IgG are very similar. Reported specificity was high but has not yet been assessed against tropical pathogens. Kit configuration: For COVID-19 Ag RDTs, flocked swabs should be added to the kit; for COVID-19 Ab RDTs, finger prick sampling materials, transfer devices, and controls should be added (currently only supplied in 15, 5, and 1/20 products). Usability and Robustness: some COVID-19 Ab RDTs showed high proportions of faint lines (>40%) or invalid results (>20%). Shortcomings were reported for buffer vials (spills, air bubbles) and their instructions for use. Stability: storage temperature was ≤30 • C for all but one RDT, in-use and result stability were maximal at 1 h and 30 min, respectively. Integration in the healthcare setting requires a target product profile, landscape overview of technologies, certified manufacturing capacity, a sustainable market, and a stringent but timely regulation. In-country deployment depends on integration in the national laboratory network. Jacobs et al. COVID-19 Rapid Tests in Sub-Saharan Africa Discussion/Conclusion: Despite these limitations, successful implementation models in triage, contact tracing, and surveillance have been proposed, in particular for COVID-19 Ab RDTs. Valuable experience is available from implementation of other disease-specific RDTs in sub-Saharan Africa.

Contact Tracing and the COVID-19 Response in Africa: Best Practices, Key Challenges, and Lessons Learned from Nigeria, Rwanda, South Africa, and Uganda

“…The GeneXpert platform, already in place for tuberculosis testing across Africa, can allow for decentralization of COVID-19 testing (beyond referral hospitals) with the use of SARS-CoV-2 cartridges. 27 However, PoC viral antigen detection is not yet sufficiently sensitive and needs further validation in Africa. 27 COVID-19-associated perceived or enacted stigma is a significant issue and has been reported from African countries.…”

“…27 However, PoC viral antigen detection is not yet sufficiently sensitive and needs further validation in Africa. 27 COVID-19-associated perceived or enacted stigma is a significant issue and has been reported from African countries. 4,28 Community sensitization through all available communication outlets, such as radio, TV, SMS messaging, social media, and other accessible platforms, is critical to debunk myths, reduce stigma to at-risk groups, and improve/ sustain public attitude and compliance.…”

COVID-19 Impact on Diagnostic Innovations: Emerging Trends and Implications

“…North America ranked third in regulatory approvals granted for diagnostic technologies (19.5%), followed by South America (10.2%) and Oceania (5.8%). Regulatory approval in Africa accounted for 1.5% of testing solutions which may be due to the limited regulatory agency resources to efficiently and effectively assess diagnostic technologies [ 105 , 106 , 107 ], in addition to limited testing infrastructure (e.g., technology, trained staff and facilities) [ 105 , 106 , 107 , 108 , 109 ].…”

“…Evidence appears to suggest that companies played a key role in enabling countries in Asia to rapidly roll-out large-scale testing programmes, by designing and manufacturing large volumes of diagnostics in these regions [ 59 , 62 , 63 , 64 , 65 , 66 ]. Our review of the literature coupled with the insights gained from our global dataset, appears to highlight that those countries with 1) limited IVD market infrastructure/research and development (R&D) capacity and 2) limited testing infrastructure (including access to diagnostic technologies, trained staff and testing facilities), were hampered in their strategic preparedness and implementation of diagnostic testing strategy’s [ 105 , 106 , 107 , 108 , 109 ].…”

“…A major challenge for low- and middle-income countries evaluating SARS-CoV-2 diagnostics, is the lack of resources to deliver a robust regulatory system. As a result, many relied on the regulatory approvals from highly regulated countries and WHO’s Emergency Use Listing (EUL) [ 107 , 108 ]. Furthermore, their fragmented healthcare and regulatory systems weaken the incentive of companies to invest (e.g., develop and commercialize products) in such a small market.…”