A Performance Assessment Study of Different Clinical Samples for Rapid COVID-19 Antigen Diagnosis Tests

Accurate diagnosis to limit the spread of SARS-CoV-2 is crucial for the clinical management of this lethal infection. Recently, many low-cost and easy-to-use rapid test kits (RTK) have been developed in many countries for the massive screening of SARS-CoV-2. Thus, evaluating the accuracy and reliability of an RTK is critical. The current study was conducted on 157 individuals to evaluate the performance accuracy of rapid SARS-CoV-2 antigen detection kits using different clinical samples compared with qRT-PCR results. Nasopharyngeal swabs were collected from patients for qRT-PCR and RTK tests, and then buccal and nasal, and nasal swabs were collected for RTK tests separately. The nasal and buccal swabs showed high sensitivity (98%) and specificity (100%) compared with the qRT-PCR results. Meanwhile, for nasal, the sensitivity was 96% with 98% specificity, and nasopharyngeal swabs showed 98% sensitivity and 94% specificity. Fisher's exact test revealed statistical significance (p < 0.05) between nasopharyngeal, nasal and buccal, and nasal swabs compared with qRT-PCR results. The study concludes that different clinical samples used for the rapid diagnosis of SARSCoV-2 showed high sensitivities and specificities compared with qRT-PCR. The RTKs using nasal and buccal, nasopharyngeal, and nasal swabs are valuable tools for the early detection of SARS-CoV-2, especially when molecular detections are available with limited access and a high infectivity rate, when the timely detection of virus cases is urgently needed. These types of clinical samples are effective to be used by RTKs for surveillance among community and healthcare workers.