Practice and thinking of emergency response drill for sudden respiratory infectious diseases

Under the corona virus disease 2019 epidemic situation, it urgently needs epidemic prevention personnel with strong comprehensive theoretical knowledge and practical experience, as well as emergency and rapid response ability. In order to effectively improve the graduates' ability to perform their duties, our university set up the subject of "emergency response drill of sudden respiratory infectious diseases" in the drill of graduates to improve their competency. This paper expounds the necessity and feasibility of the drill, discusses the practical exploration in the implementation process of the drill, and analyzes and thinks about how to further improve the effect of the drill.

Isolation and identification of two strains of severe acute respiratory syndrome coronavirus 2 from coronavirus disease 2019 patients in Shanghai

Objective To isolate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from nasal/throat swabs of coronavirus disease 19 (COVID-19) patients. Methods Three nasal/throat swab samples from COVID-19 patients in Shanghai were treated with TPCK trypsin and were used to treat Vero E6 cells inoculated in 96-well plates. When most of the cells showed obvious cytopathy, the cell culture supernatants were collected. We then detected the viral nucleic acid by fluorescent quantitative real-time polymerase chain reaction, and amplified the gene fragment of the virus receptor binding domain (RBD) by reverse transcription polymerase chain reaction. After amplification and culture, the virus was used to infect the Vero E6 cells inoculated in 96-well plates. The cytopathy was observed and the virus protein was detected by immunofluorescence. Results The Vero E6 cells that cultured with two of three nasal/pharyngeal swab samples showed obvious cytopathic effect and newly synthesized viral nucleic acid was detected in the supernatants of the cell culture. The amplified RBD sequence was completely consistent with the corresponding fragment of SARS-CoV-2 isolated earlier. Virus-infected Vero E6 cells showed cytopathies rapidly and could react with the monoclonal antibody against nucleocapsid protein (N protein) and spike protein (S protein) of SARS-CoV-2, and convalescence sera of COVID-19 patients. Conclusion Two SARS-CoV-2 strains were successfully isolated from two nasal/throat swab samples of COVID-19 patients in Shanghai, which provides evidence for the mechanism research on the infection and pathogenesis of SARS-CoV-2 as well as the development of drugs and vaccines against SARS-CoV-2.