Dong S B, Wang X L, Zhao H, Wang Y, Liu B W, Liu Y H, Pan Y, Jia L, Wang Q Y, Yang P
Institute for Infectious Disease and Endemic Disease Control, Beijing Center for Disease Prevention and Control, Beijing 100013, China.
Office of Beijing Center for Global Health, Beijing Center for Disease Prevention and Control, Beijing 100013, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2022 Apr 10;43(4):478-482. doi: 10.3760/cma.j.cn112338-20211213-00975.
To analyze the epidemiological characteristics of imported COVID-19 cases and the effect of vaccination on virus load and disease severity of the cases in Beijing. The data of the imported COVID-19 cases in Beijing were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and Epidemiology investigation. The data were processed and analyzed by Excel 2010 and SPSS 22.0. From June 1 to September 30, 2021, a total of 171 imported COVID-19 cases were reported in Beijing, of which 66.67% (114/171) were asymptomatic. The cases were mainly from the Philippines, the United Arab Emirates, the United Kingdom and the Russian Federation, accounting for 67.84% (116/171). The male to female ratio of the cases was 2∶1 (114∶57). The median age (, ) of the cases was 28 (23, 36) years. The cases of Chinese accounted for 80.12% (137/171). The sequencing of the whole genome of the virus in 47 imported COVID-19 cases showed that the proportion of Delta variant was 76.60% (36/47). The COVID-19 vaccination coverage rate in the cases was 60.82% (104/171), but the full vaccination coverage rate was 53.80% (92/171). In the imported COVID-19 cases, 13.53% (23/170) were screened to be SARS-CoV-2 nucleic acid positive on the day when they arrived in Beijing, and all the cases were positive for 2019-nCoV nucleic acid within 28 days. The severity of the disease was higher in the unvaccinated group than in the partially vaccinated group and fully vaccinated group (<0.001). In the unvaccinated group, there were 1 severe case and 1 critical case. The median values (, ) of N gene and ORFlab gene in unvaccinated group were 32.51 (23.23, 36.06) and 32.78 (24.00, 36.38), respectively. There was no significant difference in the median of double-gene value between the partially vaccinated group and the fully vaccinated group. During the study period, most of the imported COVID-19 cases in Beijing were asymptomatic. No matter vaccinated or not, the viral loads in the COVID-19 cases were similar, but the vaccination could reduce the severity of the disease.
分析北京市输入性新型冠状病毒肺炎（COVID-19）病例的流行病学特征以及疫苗接种对病例病毒载量和疾病严重程度的影响。收集北京市输入性COVID-19病例数据，来源于中国疾病预防控制信息系统的国家法定传染病报告系统及流行病学调查。采用Excel 2010和SPSS 22.0对数据进行处理与分析。2021年6月1日至9月30日，北京市共报告171例输入性COVID-19病例，其中无症状感染者占66.67%（114/171）。病例主要来自菲律宾、阿拉伯联合酋长国、英国和俄罗斯联邦，占67.84%（116/171）。病例男女比例为2∶1（114∶57）。病例中位年龄（，）为28（23，36）岁。中国籍病例占80.12%（137/171）。47例输入性COVID-19病例病毒全基因组测序结果显示，Delta变异株占76.60%（36/47）。病例中COVID-19疫苗接种率为60.82%（104/171），但全程接种率为53.80%（92/171）。在输入性COVID-19病例中，13.53%（23/170）在抵达北京当日筛查新型冠状病毒（SARS-CoV-2）核酸呈阳性，所有病例在28天内新型冠状病毒肺炎（2019-nCoV）核酸均为阳性。未接种疫苗组疾病严重程度高于部分接种疫苗组和全程接种疫苗组（<0.001）。未接种疫苗组有1例重症病例和1例危重症病例。未接种疫苗组N基因和ORF1ab基因的中位数值（，）分别为32.51（23.23，36.06）和32.78（24.00，36.38）。部分接种疫苗组和全程接种疫苗组双基因数值中位数差异无统计学意义。研究期间，北京市大多数输入性COVID-19病例为无症状感染者。无论是否接种疫苗，COVID-19病例的病毒载量相似，但接种疫苗可降低疾病严重程度。
