Diagnostic Accuracy of SARS-CoV-2 Nucleocapsid Antigen Self-Test in Comparison to Reverse Transcriptase-Polymerase Chain Reaction.

BACKGROUND: Currently, the rapid antigen test (RAT) and reverse transcriptase-polymerase chain reaction (RT-PCR) are considered the main stakeholders in COVID-19 diagnosis. In RT-PCR, any of at least 2 evolutionary conserved genes (RdRP, E-, N-, ORF1ab gene) and S-gene of SARS-CoV-2 are endorsed, and in RAT, the nucleocapsid antigen (N-Ag) of SARS-CoV-2 is considered due to its stability and fewer chances of mutation effects. In the present work, we evaluated the performance of the AG-Q COVID-19 N-Ag self-test kit and conducted a validation study in comparison with the RT-PCR. METHODS: AG-Q COVID-19 N-Ag rapid test kit is an Indian Council of Medical Research (ICMR) approved product developed and marketed by Agappe Diagnostics Limited. The RT-PCR assay was performed with a COVIPATH COVID-19 RT-PCR kit from Thermo Fisher Scientific. RESULTS: We observed 19 false-negative results in antigen self-tests, including samples of threshold cycle (Ct) values 22/22 (N-gene/ORF1ab-gene) in RT-PCR, indicating inadequate sampling by the patients in self-tests, leading to false-negative results and increased chances of the disease spreading. Based on the RT-PCR Ct value vs antigen self-test comparison, it is evident that proper sampling is crucial in performing antigen self-tests. Also, there were weak positive results in antigen self-tests with a Ct value of 18/19 in RT-PCR. CONCLUSIONS: Although the sensitivity and diagnostic accuracy offered by the AG-Q COVID-19 N-Antigen self-test in comparison with RT-PCR fulfills the ICMR tenets for RAT, this study recommends the laboratory/hospital-based RAT execution would be appropriate, rather than the self-test.

Evaluation of the Safety and Efficacy of Favipiravir in Adult Indian Patients with Mild-to-Moderate COVID-19 in a Real-World Setting.

Purpose: To evaluate the safety and efficacy of favipiravir, which is prescribed for the treatment of patients with mild-to-moderate coronavirus disease 2019 (COVID-19) in India. Patients and Methods: This was a prospective, open-label, multicenter, single-arm postmarketing study conducted in India. Patients with mild-to-moderate COVID-19 received favipiravir (3600 mg [1800 mg orally twice daily] on the first day, followed by 800 mg orally twice daily, up to a maximum of 14 days) as a part of their treatment. The primary endpoints were to evaluate the safety of favipiravir by assessing the number of adverse events (AEs) and treatment-related AEs. The secondary endpoints were to evaluate the efficacy of favipiravir by assessing time to clinical cure, rate of clinical cure, time to pyrexia resolution, rate of oxygen requirement, and all-cause mortality. Results: A total of 1083 patients were enrolled in this study from December 2020 to June 2021. Adverse events were reported in 129 patients (11.9%), 116 (10.7%) of whom had mild AEs. Dose modification or withdrawal of favipiravir treatment was reported in four patients (0.37%). The median time to clinical cure and pyrexia resolution was 7 and 4 days, respectively. A total of 1036 patients (95.8%) exhibited clinical cure by day 14. Oxygen support was required by 15 patients (1.4%). One death was reported, which was unrelated to favipiravir. Conclusion: In the real-world setting, favipiravir was well-tolerated, and no new safety signals were detected.