BackgroundRapid antigen tests can help in the effective isolation of symptomatic cases and the systematic tracing of close contacts. However, their reliability must be validated before implementing them widely.MethodsA cross-sectional study was conducted on 236 COVID-19-suspected patients visiting four different health institutions in Harari Regional State, Harar, Eastern Ethiopia, from June to July 2021. Two nasopharyngeal samples were collected and processed by the Panbio™ Ag-RDT kit and qRT-PCR. The collected data were analyzed using SPSS version 25.0.ResultsThe Panbio tests had a sensitivity of 77.5% (95% CI: 61.6–89.2%) and a specificity of 98.5% (95% CI: 95.6–99.7%). It also had a positive predictive value of 91.2% (95% CI: 76.9–96.9%), a negative predictive value of 95.5% (95% CI: 92.3–97.4%), and a kappa of 0.81 (95% CI: 0.7–0.9). The test had a sensitivity of 94.4%, 100%, 100%, and 90% in the samples collected from patients within the 1–5 days post-onset of COVID-19 signs and symptoms, of age group ≤18 years old, with cycle threshold values of <20, and with household contact, respectively.ConclusionThis test can be used as point-of-care testing for the diagnosis of symptomatic patients with short clinical courses and contact with patients in households.

Rapid Antigen tests can help rapid detection, effective isolation of symptomatic cases, and systematic tracing of close contacts. However, the reliability of rapid antigen tests must be validated before they can be used widely. A cross-sectional study was conducted among 236 COVID-19 suspected patients visiting four health institutions in Harari Regional state, Harar, Eastern Ethiopia from June-July, 2021. Two Nasopharyngeal samples were also collected and processed by the Panbio™ Ag-RDT kit directly and RT-PCR. Data were analyzed using SPSS version 25.0. The Panbio tests has sensitivity of 77.5% (95% CI: 61.6% − 89.2%), specificity of 98.5% (95% CI: 95.6%- 99.7%), Positive Predictive Value of 91.2% (95% CI : 76.9% − 96.9%), negative Predictive Value of 95.5%(95%CI: 92.3%-,97.4%) and Kappa = 0.81, (95% CI: 0.7–0.9.).The test has sensitivity of 94.4% ,100%, 100% and 90% in sample collected from patients with in the 1–5 days duration of COVID post on set symptoms, age group < = 18 years old and cycle threshold (Ct) values of < 20 and source of contact from house hold respectively .The overall sensitivity of Panbio™ COVID-19 Ag Rapid Test Device is 77.5%. The test has sensitivity > = 90% in the sample collected from symptomatic patients in early clinical course, age of < = 18 years old, low Ct-values, and had contact with COVID patients in the household. Therefore, this test can be used as a point of care testing for diagnosis of symptomatic patients with shorted clinical course and contact with patients in the households.