Clinical performance of rapid antigen tests in comparison to RT-PCR for SARS-COV-2 diagnosis in Omicron variant: A systematic review and meta-analysis.

The Omicron variant of concern has a high level of mutations in different genes that has raised awareness about the performance of immunological products such as vaccines and antigen detection kits. In this systematic review and meta-analysis, we investigated whether Omicron had a significant influence on rapid antigen test (RAT) performance in comparison to PCR. We registered this systematic review and meta-analysis in PROSPERO with the registration number CRD42022355510. We searched PubMed, Scopus, Embase, and Web of Science databases systematically to 1 August 2022. After article screening, we assessed the quality of the included studies based on the JBI checklist. Following data extraction, we performed a meta-analysis using R software. We included 18 qualified articles presenting sufficient data about RATs performance in comparison to RT-PCR in Omicron infections. The pooled specificity and sensitivity of RATs were 1.000 (0.997-1.000) and 0.671 (0.595-0.721), respectively. The FDA-approved kits showed a better performance than WHO-approved ones with a sensitivity of 0.728 (0.620-0.815). The use of RATs with nasal swabs showed a higher sensitivity compared with nasopharyngeal swabs. The sensitivity for samples with a CT-value >25 was 0.108 (0.048-0.227). Rapid antigen tests show impaired performance for COVID-19 diagnosis when the Omicron variant is circulating, particularly in samples with low viral loads.

Mucormycosis in pre-COVID-19 and COVID-19 era: A study of prevalence, risk factors and clinical features.

Objective: Mucormycosis is a rare yet devastating fungal disease with a frequently fatal outcome. The purpose of this study was to compare the prevalence of mucormycosis, evaluate its risk factors, and assess the patients' outcomes in pre-COVID-19 and COVID-19 era. Methods: In this retrospective observational study, clinical data of 158 patients with confirmed histopathological diagnosis of mucormycosis were collected from the medical records departments of Imam Reza and Ghaem hospitals, Mashhad, Iran during 2018-2021. The collected data were risk factors associated with mucormycosis including age, gender, underlying diseases, details of corticosteroid administration, and complications such as blindness and mortality. Results: Of 158 studied patients, 48 patients were diagnosed in the pre-pandemic period whereas 110 cases were admitted during the pandemic era. COVID-19 associated mucormycosis (CAM) was observed in 58.1% of the pandemic cases. In the pre-pandemic period, cancer (89.5% vs. 39%, p < .001) was significantly more prevalent while during the pandemic era, the prevalence of diabetes mellitus (16.7% vs. 51%, p < .001) was remarkably higher. Moreover, the mortality rate of mucormycosis was considerably reduced after the pandemic (64.6%-45.4%), especially in CAM patients (35.9%). Conclusion: The COVID-19 pandemic has led to an increased prevalence of mucormycosis, due to the convergence of interlinked risk factors such as diabetes mellitus, corticosteroid therapy, and COVID-19. Therefore, clinicians must be aware of the probable occurrence of mucormycosis in the first or second week of COVID-19 infection in vulnerable patients and use the steroids cautiously. Level of evidence: 4 Laryngoscope Investigative Otolaryngology, 2022.