Abstract：Objective To learn the epidemiological characteristics of coronavirus disease 2019 (COVID-19) cases reported from January 21 to February 20,2020 in Zhejiang Province,so as to provide basis for formulating and implementing effective control measures. Methods The COVID-19 cases reported by Zhejiang Province were extracted from the National Diseases Prevention and Control Information System. A descriptive analysis was adopted for the epidemiological characteristics of COVID-19 cases,including time,spatial and population distribution,severity of symptoms, and exposure history. Results Totally 1 284 cases were reported,of which 1 176 were confirmed cases (91.59%) and 108 were asymptomatic cases (8.41%). The first confirmed case was reported on January 21. The curve of the disease onset peaked from January 22 to 29, with 87 cases as the biggest number a day. The curve of the disease reported peaked from January 28 to 30, with 130 cases as the biggest number a day. Then the number of the cases showed a declining trend. By February 4, totally 79 counties (cities, districts) had confirmed cases, covering 87.78% of Zhejiang Province, and it has not increase since then. A male to female ratio of 1.02∶1 was reported among 1 284 cases,1 021 were 30-69 years old (79.52%) and 339 (26.40%) were business service providers. There were 11 health workers reported to be infected,but not by occupational exposure. Among the confirmed cases, 1 010 (85.88%) were clinically mild cases. One case died. Before January 23, the cases were mainly imported from Hubei Province, local cases were predominant by the end of January. Conclusions The COVID-19 epidemic has spread widely in Zhejiang Province and people are generally susceptible. Most cases were clinically mild, and were aged 30-69 years. No health workers infected were due to occupational exposure. The incidence of COVID-19 in Zhejiang Province has turned into a lower level,suggesting that the early prevention and control measures have achieved initial results. With people returning from holiday, precise prevention and control should be put into effect.
 WANG C,HORBY P W,HAYDEN F G,et al.A novel coronavirus outbreak of global health concern[J]. Lancet, 2020, 395(10223):470-473.  武汉市卫生健康委员会. 武汉市卫健委关于当前我市肺炎疫情的情况通报 [EB/OL]. (2019-12-31) [2020-02-28]. http://www.wuhan.gov.cn/front/web/showDetail/2019123108989.  ZHU N,ZHANG D,WANG W,et al.A novel coronavirus from patients with pneumonia in China,2019[J]. N Engl J Med,2020,382(8):727-733.  National Center for Immunization and Respiratory Diseases (NCIRD), Division of Viral Diseases. Coronavirus Disease2019 (COVID-19) in the U.S. [EB/OL].(2020-02-21) [2020-02-28]. https://www.cdc.gov/coronavirus/2019-ncov/cases-in-us.html.  PONGPIRUL W A,PONGPIRUL K,RATNARATHON A C,et al. Journey of a Thai taxi driver and novel coronavirus[J/OL]. N Engl J Med(2020-02-12)[2020-02-28]. https://www.nejm.org/doi/full/10.1056/NEJMc2001621?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed.  ROTHE C,SCHUNK M,SOTHMANN P,et al. Transmission of2019-nCoV Infection from an Asymptomatic Contact in Germany[J/OL]. N Engl J Med(2020-01-30)[2020-02-28]. https://www.nejm.org/doi/full/10.1056/NEJMc2001468?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed.  中国疾病预防控制中心新型冠状病毒肺炎应急响应机制流行病学组. 新型冠状病毒肺炎流行病学特征分析[J]. 中华流行病学杂志,2020,41(2):145-151.  中华人民共和国国家卫生健康委员会办公厅. 新型冠状病毒肺炎防控方案(第五版)[EB/OL].(2020-02-21)[2020-02-28]. http://www.nhc.gov.cn/jkj/s3577/202002/a5d6f7b8c48c451c87dba14889b30147/files/3514cb996ae24e2faf65953b4ecd0df4.pdf.  中华人民共和国国家卫生健康委员会办公厅,中华人民共和国国家中医药管理局办公室.新型冠状病毒肺炎诊疗方案(试行第六版)[EB/OL].(2020-02-21)[2020-02-28]. http://www.nhc.gov.cn/yzygj/s7653p/202002/8334a8326dd94d329df351d7da8aefc2 /files/b218cfeb1bc54639af227f922bf6b817.pdf.  浙江省人民政府. 袁家军:10大最严格措施防控新型肺炎[EB/OL].(2020-01-24)[2020-02-28]. http://www.zj.gov.cn/art/2020/1/24/art_1554467_41855124.html.  中华预防医学会新型冠状病毒肺炎防控专家组. 新型冠状病毒肺炎流行病学特征的最新认识[J].中华流行病学杂志,2020,41(2):139-144.  LINTON N M,KOBAYASHI T,YANG Y,et al.Incubation period and other epidemiological characteristics of 2019 novel coronavirus infections with right truncation:a statistical analysis of publicly available case data[J]. J Clin Med,2020,9(2):538.