ABSTRACT
ObjectiveTo describe the epidemic characteristics of COVID-19 after policy adjustment from “Category B notifiable disease with category A management” to “Category B notifiable disease with category B management”， and to explore the protective effect of previous infection with SARS-CoV-2 on common symptoms of reinfection. MethodsHealthcare workers infected with SARS-CoV-2 in a grade A tertiary hospital in Shanghai were included in the study from December 4， 2022 to January 11， 2023. Data on demographic characteristics， clinical symptoms， medical history， and COVID-19 vaccination history were collected. We determined the epidemiological curve and characteristics， and then compared the difference in the severity of clinical symptoms between primary and reinfection subjects. ResultsA total of 2 704 cases were included in the study， of which 45 had reinfection， 605 （22.4%）were males， 608 （22.5%）were doctors， 1 275 （47.2%） were nurses， and 2 351 （86.9%） received ≥3 doses of COVID-19 vaccination. The average age of these healthcare workers was （34.9±9.1） years old. The number of cases with mild/moderate illness， asymptomatic infection， fever， headache， dry cough， expectoration， and chest tightness were 2 704 （100.0%）， 92 （3.4%）， 2 385 （88.2%）， 2 066 （76.4%）， 1 642 （60.7%）， 1 807 （66.8%）， and 439 （16.2%）， respectively. Reinfection was a protective factor for fever （OR=0.161， P<0.001）， headache （OR=0.320， P<0.001）， and peak body temperature （β=-0.446， P<0.001）. ConclusionFollowing the COVID-19 policy adjustment as a category B notifiable disease， healthcare workers at a grade A tertiary hospital in Shanghai predominantly experiences mild to moderate COVID-19 symptoms. Reinfection results in milder clinical manifestations， with a lower proportion of being asymptomatic.
ABSTRACT
BACKGROUND:Although the therapeutic effect of total knee arthroplasty for severe gonarthritis is reliable, deep vein thrombosis also occurred in many patients. Therefore, deep vein thrombosis has been a major reason for unexpected death after total knee arthroplasty. OBJECTIVE:To study the incidence of deep vein thrombosis after total knee arthroplasty with general and epidural anesthesia. METHODS:We searched“PubMed”,“Medline”,“Elsevier”,“Embase”, Cochrane library,“Wanfang”,“China National Knowledge Infrastructure”for papers published from January 2000 to March 2015. The mesh words were“total knee arthroplasty”,“TKA”,“thrombosis”,“DVT”,“randomized control ed trial”,“RCT”for studies concerning deep vein thrombosis after total knee arthroplasty with different anesthetic methods. The double blind method was used for data extraction and assessment of literature quality. Revman5.3 software was utilized to analyze the extracted data using meta-analysis. RESULTS AND CONCLUSION:There were 8 studies including 885 patients. The heterogeneity of the included studies was very low (I2=0, P=0.72). The combined OR was 0.25 (95%confidence interval:0.18, 1.35), indicating that continuous epidural anesthesia in total knee arthroplasty could apparently reduce the possible formation of postoperative deep vein thrombosis. Because of lack of the changes in coagulation factors under general anesthesia and epidural anesthesia, the mechanism underlying epidural anesthesia to reduce the incidence of deep vein thrombosis deserves further investigations. Among patients with deep vein thrombosis, continuous epidural anesthesia could diminish the possible formation of deep vein thrombosis. Thus, epidural anesthesia should be used firstly for knee replacement in patients with high risk of deep vein thrombosis.