Developing a reproducible quality COVID-19 RDT proficiency testing scheme: A rapid response to quality assured COVID-19 point of care testing

Introduction : Reliable approaches for evaluating the competency of health workers in performing SARS-CoV-2 antigen rapid diagnostic tests (Ag-RDTs) remain limited across sub-Saharan African laboratories, community settings, and primary health facilities. To address this gap, the WHO Supranational Reference Laboratory in Kampala, Uganda, established a proficiency testing (PT) program. Methods: SARS-CoV-2 antigen PT panels were developed at the Kampala SRL and distributed to 12 sub-Saharan countries. Each round involved five blinded PT samples, provided twice annually to 764 testing sites between November 2021 and November 2024. Competency was evaluated by comparing reported results with expected outcomes, assigning percentage scores, and delivering feedback reports. Results: The PT materials demonstrated stability for up to 56 days at temperatures as high as 46°C. The average pass rate exceeded 87% across all rounds, with the highest performance reaching 95%. Participation across the 12 countries declined from 53.1% to 38.1% over three years, primarily due to reduced COVID-19 testing demand. Conclusion: This study shows that the developed SARS-CoV-2 antigen PT panels are a feasible option for external quality assessment in resource-limited settings. Strengthening quality management systems, providing refresher training, and expanding PT programs to remote facilities are critical for sustaining high-quality COVID-19 diagnostics.