[Establishment and preliminary application of quantitative real-time PCR assay for the detection of SARS-CoV-2 subgenomic nucleocapsid RNA].

Objective: To establish a rapid and specific quantitative real-time PCR (qPCR) method for the detection of SARS-CoV-2 subgenomic nucleocapsid RNA (SgN) in patients with COVID-19 or environmental samples. Methods: The qPCR assay was established by designing specific primers and TaqMan probe based on the SARS-CoV-2 genomic sequence in Global Initiative of Sharing All Influenza Data (GISAID) database. The reaction conditions were optimized by using different annealing temperature, different primers and probe concentrations and the standard curve was established. Further, the specificity, sensitivity and repeatability were also assessed. The established SgN and genomic RNA (gRNA) qPCR assays were both applied to detect 21 environmental samples and 351 clinical samples containing 48 recovered patients. In the specimens with both positive gRNA and positive SgN, 25 specimens were inoculated on cells. Results: The primers and probes of SgN had good specificity for SARS-CoV-2. The minimum detection limit of the preliminarily established qPCR detection method for SgN was 1.5×102 copies/ml, with a coefficient of variation less than 1%. The positive rate of gRNA in 372 samples was 97.04% (361/372). The positive rates of SgN in positive environmental samples and positive clinical samples were 36.84% (7/19) and 49.42% (169/342), respectively. The positive rate and copy number of SgN in Wild strain were lower than those of SARS-CoV-2 Delta strain. Among the 25 SgN positive samples, 12 samples within 5 days of sampling time were all isolated with virus; 13 samples sampled for more than 12 days had no cytopathic effect. Conclusion: A qPCR method for the detection of SARS-CoV-2 SgN has been successfully established. The sensitivity, specificity and repeatability of this method are good.

Longitudinal Assessment for Anxiety and Depression among Frontline Medical Staff at a Specialized Hospital to Admit Patients with COVID-19

Longitudinal alterations of mental health problems still lack clarity among frontline medical staff treating patients with coronavirus disease 2019 (COVID-19). Mental health surveys were conducted from February 19 to 23 (n = 222), from March 3 to 10 (n = 364), from March 15 to 22 (n = 446), and from March 25 to April 3 (n = 174), 2020, of medical staff working at medical staff at a specializ ed hospital to admit patients with COVID-19 in China. The rate of reporting anxiety remained unchanged within 6 weeks, but the rate of reporting depression increased at week 3 and remained unchanged afterwards. Age was an independent risk factor for symptoms of anxiety and depression, and working days were independent risk factors for symptoms of depression. These results highlight the importance of dynamic assessment. Copyright © 2022, Universidade de Sao Paulo. Museu de Zoologia. All rights reserved.