Abstract:
Objective: To evaluate the accuracy of the COVID-19 Ag Rapid test device for detection of SARS-CoV-2 with Reverse Transcriptase Polymerase Chain Reaction as the gold standard. Study Design: Cross-sectional study. Place and Duration of Study: Department of Virology, Armed Forces Institute of Pathology, Rawalpindi, in the month of Sept 2020. Methodology: A total of 106 patients suspected of COVID-19 were tested, including 63 patients admitted to the COVID-19 ward of Pak Emirates Military Hospital and 43 from the emergency department of Combined Military Hospital, Rawalpindi Pakistan respectively. The samples were transported to the Virology department and subjected to Polymerase Chain Reaction and Antigen testing. In addition, the diagnostic accuracy of the COVID-19 Ag Rapid test device was compared to Reverse Transcriptase Polymerase Chain Reaction for detection of SARS-CoV-2 infection. Results: Out of 106 nasopharyngeal swab samples tested, 48 (45.2%) samples were positive by Rapid test device and Reversed Transcriptase Polymerase Chain Reaction, and 52 (49.0%) samples tested negative by both methods. Inconsistent results (False Negative) were obtained in 6 (5.6%) samples. COVID-19 Ag Rapid test device has detected the maximum number of cases, 41 (85.4%), during the first week of illness. Its sensitivity decreases as the duration of infection progress. Conclusion: The overall sensitivity of the Rapid test device is much less than the Polymerase chain reaction due to potential false negative results. However, it can be helpful in the early isolation of cases in an outbreak in a closed community and for case management in peripheral setups, where Polymerase chain reaction facilities are unavailable.