ABSTRACT
BackgroundRapid diagnostics are vital for curving the transmission and control of COVID-19 pandemic. Although many commercially available antigen-based rapid diagnostic tests (Ag-RDTs) for the detection of SARS-CoV-2 are recommended by the WHO, their diagnostic performance has not yet been assessed in Ethiopia. So far, the vast majority of studies assessing diagnostic accuracies of rapid antigen tests considered RT-PCR as a gold standard, which inevitably leads to bias when RT-PCR is not 100% sensitive and specific. Thus, this study aimed to evaluate the diagnostic performance of Panbio COVID-19 rapid antigen test jointly together with the RT-PCR for the detection of SARS-CoV-2. MethodsA prospective cross-sectional study was done from July to September 2021 in Addis Ababa, Ethiopia, during the third wave of the pandemic involving two health centers and two hospitals. Diagnostic sensitivity and specificity of Panbio rapid antigen test and RT-PCR were obtained using Bayesian Latent-Class Models (BLCM). Results438 COVID-19 presumptive clients were enrolled, 239 (54.6%) were females, of whom 196 (44.7%) had a positive RT-PCR and 158 (36.1%) were Ag-RDT positive. The Ag-RDT and RT-PCR had a sensitivity (95% CrI) of 99.6 (98.4-100), 89.3 (83.2-97.6) and specificity (95% CrI) of 93.4 (82.3 - 100), 99.1 (97.5-100) respectively. Most of the study participants, 318 (72.6) exhibited COVID-19 symptoms and the most reported was cough 191 (43.6). ConclusionThe diagnostic performance of Panbio COVID-19 Ag RDT is coherent with the WHO established criteria of having a sensitivity [≥]80% for Ag-RDTs. Superior performance of the Panbio RDT was documented in samples with the lowest cycle-threshold RT-PCR values and clients with confirmed clinical symptoms. Thus, we recommend the use of the Panbio RDT for both symptomatic and asymptomatic individuals in clinical settings for screening purposes.
