|
|
|
| Epidemiological characteristics of local COVID-19 cases in Zhejiang Province |
| WANG Zhen, LIU Biyao, QI Xiaohua, ZHANG Renjie, BIAN Qiao, JIANG Min
|
| Department of Health Emergency, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang 310051, China |
|
|
|
|
Abstract Objective To analyze the epidemiological characteristics of coronavirus disease 2019 (COVID-19) local infections in Zhejiang Province during the period between March and May, 2022, so as to provide the evidence for COVID-19 control. Methods The individual investigation data and field epidemiological investigation data of local COVID-19 cases in Zhejiang Province from March to May 2022 were extracted from the National Diseases Prevention and Control Information System of China. The temporal, spatial and population distribution, identification and booster vaccination of local COVID-19 cases were analyzed using a descriptive epidemiological method. Factors affecting the severity of clinical symptoms were identified among local COVID-19 cases using a multivariable logistic regression model. Results A total of 289 local COVID-19 epidemics occurred in Zhejiang Province from March to May 2022, and all infections were caused by the Omicron variant. A total of 1 598 local COVID-19 infections were reported, including 672 confirmed cases (42.05%) and 926 asymptomatic cases (57.95%), and the 672 confirmed case included 614 mild cases (91.37%), 58 normal cases (8.63%), while no severe, critically ill or dead cases were reported. The mean duration of COVID-zero community, mean duration of COVID-19 epidemics and mean length to COVID-19 peak calculated according to 7 epidemics with 50 and more cases were (6.14±1.07), (13.43±4.39), (3.00±1.63) d, respectively. COVID-19 infection was predominantly detected in centralized quarantine sites (1 105 cases, 69.15%), and 843 cases completed booster immunization of COVID-19 vaccines (52.75%). Multivariable logistic regression analysis showed that age (with ages of 60 years and older as the reference, age of 6 to 17 years, OR=0.111, 95%CI: 0.024-0.508; age of 18 to 44 years, OR=0.341, 95%CI: 0.163-0.713) and booster COVID-19 vaccination (OR=0.219, 95%CI: 0.117-0.410) were protective factors for developing more severe clinical symptoms following COVID-19 infections. Conclusions All local COVID-19 infections were caused by Omicron variant in Zhejiang Province during the period between March and May 2022, and all cases had mild clinical symptoms. Preschool children, middle-aged and elderly residents and individuals that did not complete booster COVID-19 vaccination may had relatively more severe clinical symptoms following COVID-19 infections.
|
|
Received: 29 June 2022
Revised: 20 October 2022
Published: 13 December 2022
|
|
|
|
|
|
[1] World Health Organization.Tracking SARS-CoV-2 variants[EB/OL].(2022-01-15)[2022-10-20].https://www.who.int/en/activities/tracking-SARS-CoV-2-variants.
[2] RATHINASAMY M,KANDHASAMY S.An exploratory study on the propagation of SARS-CoV-2 variants:Omicron is the most predominant variant[J].J Med Virol,2022,94(6):2414-2421.
[3] 中华人民共和国国家卫生健康委员会.国务院联防联控机制2022年5月6日新闻发布会文字实录[EB/OL].(2022-05-06)[2022-10-20].http://www.nhc.gov.cn/xcs/fkdt/202205/3e4f3e39b27f4c5fa331149e19c88039.shtml.
[4] 浙江省人民政府.浙江省新冠肺炎疫情防控工作新闻发布会(第一百一十六场)[EB/OL].(2022-04-28)[2022-10-20].http://www.zj.gov.cn/art/2022/4/28/art_1229630150_1539.html.
[5] 国务院应对新型冠状病毒肺炎疫情联防联控机制综合组.新型冠状病毒肺炎防控方案(第八版)[EB/OL].(2021-05-11)[2022-10-20].http://www.nhc.gov.cn/jkj/s3577/202105/6f1e8ec6c4a540d99fafef52fc86d0f8/files/01f13e0ae31947ce8141a7b21439e285.pdf.
[6] 中华人民共和国国家卫生健康委员会办公厅,国家中医药管理局办公室.新型冠状病毒肺炎诊疗方案(试行第九版)[EB/OL].(2022-03-14)[2022-10-20].http://www.nhc.gov.cn/yzygj/s7653p/202203/b74ade1ba4494583805a3d2e40093d88/files/ef09aa4070244620b010951b088b8a27.pdf.
[7] 黄云,李依红,谢仕兰,等.新型冠状病毒Omicron变异株研究进展[J].中华流行病学杂志,2022,43(5):655-662.
HUANG Y,LI Y H,XIE S L,et al.Progress in research of 2019-nCoV Omicron variant[J].Chin J Epidemiol,2022,43(5):655-662.
[8] PEACOCK T P,BROWN J C,ZHOU J,et al.The altered entry pathway and antigenic distance of the SARS-CoV-2 Omicron variant map to separate domains of spike protein[EB/OL].BioRxiv,2022[2022-06-21].https://doi.org/10.1101/2021.12.31.474653.
[9] WILHELM A,WIDERA M,GRIKSCHEIT K,et al.Reduced neutralization of SARS-CoV-2 Omicron variant by vaccine sera and monoclonal antibodies[EB/OL].medRxiv,2021[2022-10-20].https://doi.org/10.1101/2021.12.07.21267432.
[10] Pfizer and BioNTech Provide Update on Omicron Variant[EB/OL].(2021-12-08) [2022-10-20].https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-provide-update-omicron-variant.
[11] AI J,ZHANG H,ZHANG Q,et al.Recombinant protein subunit vaccine booster following two-dose inactivated vaccines dramatically enhanced anti-RBD responses and neutralizing titers against SARS-CoV-2 and Variants of Concern[J].Cell Res,2022,32(1):103-106.
[12] 李宇,张哲,杜溪乔,等.新冠病毒变异株Omicron的变异特点及对免疫学特性的影响[J].国际免疫学杂志,2022,45(1):1-4.
LI Y,ZHANG,DU X Q,et al.Genomic variation characteristics and immunological effects of a novel SARS-CoV-2 variant,Omicron[J].Int J Immunol,2022,45(1):1-4.
[13] 施长苗,敖新华,邵斌,等.入境人员集中隔离点新型冠状病毒核酸检测阳性病例特征分析[J].预防医学,2022,34(4):325-329.
SHI C M,AO X H,SHAO B,et al.Characteristics of individuals positive for SARS-CoV-2 nucleic acid in a centralized isolation site for people entering China[J].Prev Med,2022,34(4):325-329. |
|
|
|
