[Experience and thinking on the normalization stage of prevention and control of COVID-19 in China].

COVID-19 is an important public health issue of great concern at home and abroad, and it is still in the state of global pandemic. During the normalization stage of prevention and control of the epidemic of COVID-19, China effectively controlled the outbreak and spread of the epidemic by adopting the strategy of "import of external prevention and rebound of internal prevention", and effectively reduced the occurrence of death cases. The social economy recovered quickly, and various measures were highly recognized by the public, and the positive trend of the epidemic continued to consolidate. At present, although the spread of the local epidemic has been basically stopped, the international epidemic continues to rise rapidly, and the pressure of "imported prevention and control" in China continues to increase. Considering the characteristics of the normalization of epidemic prevention and control and the particularity of the virus, the connotation of the normalization of epidemic prevention and control should be understood scientifically. The prevention and control goal of the epidemic in the normalization stage should be to maximize early detection, early treatment and early disposal, and resolutely prevent the continuous spread of the epidemic in communities, that is, to prevent the infection as much as possible, and resolutely prevent the rebound (sustained spread in communities), rather than "zero infection". The prevention and control policy of "timely detection, rapid disposal, precise management and control, and effective treatment" has been implemented in various localities, and a series of effective and regular experience in prevention and control has been formed in the practice of prevention and control. Winter and spring are the key periods for the prevention and control of the epidemic. We should continue to work together to prevent and control the epidemic, fulfill the responsibilities of all parties, and prevent and control the epidemic in a scientific and effective way.

[Comparison of severity classification of Chinese protocol, pneumonia severity index and CURB-65 in risk stratification and prognostic assessment of coronavirus disease 2019].

Objective: To investigate the application of severity classification according to the protocol on the Diagnosis and Treatment of coronavirus disease 2019(COVID-19)by the National Health Commission of China, pneumonia severity index(PSI) and CURB-65　in risk stratification and prognostic assessment of COVID-19. Methods: Clinical data of 234 in-hospital patients with COVID-19 were collected and retrospectively reviewed in Wuhan Tongji Hospital. Patients were divided into 3 groups (common, severe, and critical type) at admission according to the sixth version of the protocol issued by the National Health Commission of China on Diagnosis and Treatment of COVID-19. At the same time, the severity of pneumonia was calculated by PSI and CURB-65, and the patients were stratified into 3 risk groups, namely mild, moderate, and severe groups. The hospital mortality rate was evaluated in each group. Sensitivity, specificity, positive predictive values, negative predictive values, and the area under the receiver operating characteristic(ROC) curve(AUC) for predicting hospital mortality in each rule were assessed. Results: According to the severity classification of Chinese protocol, the proportion of patients with common type, severe type, and the critical type was 15.8%, 75.6%, and 8.5%, respectively. No in-hospital death occurred in the common type. As for PSI and CURB-65, greater proportions of patients were classified as low risk(79.1% and 75.6%, respectively), while smaller proportions of patients were classified as moderate and high risk(16.2%, 15.0%; 4.7%, 9.4%, respectively). In-hospital death occurred in low and moderate risk patients identified by these 2 scoring systems. The mortality of the critical group of the Chinese protocol was 65%, and the sensitivity and specificity of predicting in-hospital mortality were 36.4% and 97.0%, respectively. The mortality in the high risk group of PSI and CURB-65 was 100% and 77.3%. The risk class V of PSI and CURB-65 score 3-5 had high specificity(100% and 97.4%, respectively)but low sensitivity(33.3% and 51.5%, respectively)in predicting in-hospital mortality. The AUC of the Chinese protocol severity classification, PSI, and CURB-65 was 0.735, 0.951, and 0.912. The optimal cut-off point of PSI was risk class Ⅳ, and the sensitivity and specificity for predicting mortality were 90.9% and 90.5%. The optimal cut-off point of CURB-65 was score 2, and the corresponding sensitivity and specificity were 84.8% and 85.6%. Conclusions: PSI and CURB-65 can be used for risk stratification and prognostic assessment in patients with COVID-19.