Laboratory and field evaluation of the STANDARD Q and PanbioTM SARS-CoV-2 antigen rapid test in Namibia using nasopharyngeal samples

Konstantinus, I. S.; Chiwara, D.; Ndevaetela, E.-E.; Ndarukwa-Phiri, V.; Garus-oas, N.; Frans, N.; Ndumbu, P.; Shiningavamwe, A.; van Rooyen, G.; Schiceya, F.; Hlahla, L.; Namundjebo, P.; Ndozi-Okia, I.; Chikuse, F.; Hailu Bantiewalu, S.; Tjombonde, K.

Abstract Background As new SARS-CoV-2 variants of concern emerge, there is a need to scale up testing to minimize transmission of the Coronavirus disease 2019 (COVID-19). Many countries especially those in the developing world continue to struggle with scaling up reverse transcriptase polymerase reaction (RT-PCR) to detect SARS-CoV-2 due to scarcity of resources. Alternatives such as antigen rapid diagnostics tests (Ag-RDTs) may provide a solution to enable countries to scale up testing. Methods In this study, we evaluated the PanbioTM and STANDARD Q Ag-RDTs in the laboratory using 80 COVID-19 RT-PCR confirmed and 80 negative nasopharyngeal swabs. The STANDARD-Q was further evaluated in the field on 112 symptomatic and 61 asymptomatic participants. Results For the laboratory evaluation, both tests had a sensitivity above 80% (PanbioTM = 86% vs STANDARD Q = 88%). The specificity of the PanbioTM was 100%, while that of the STANDARD Q was 99%. When evaluated in the field, the STANDARD Q maintained a high specificity of 99%, however the sensitivity was reduced to 56%. Conclusion Using Ag-RDTs in low resource settings will be helpful, however, negative results should be confirmed by RT-PCR where possible to rule out COVID-19 infection.