Objective:To analyze the epidemiological characteristics of clustered outbreaks in the early stage of the coronavirus disease 2019 (COVID-19) epidemic in Haidian district, Beijing, so as to provide reference for future epidemic prevention and control.Methods:The data of patients in the COVID-19 clustered outbreaks in Haidian district from January 20 to February 28, 2020 were collected, and the characteristics of the epidemic were analyzed by descriptive epidemiological methods.Results:In the early stage of the epidemic, a total of 13 clustered outbreaks occurred in Haidian District, involving 45 infected patients, including 5 deaths. The outbreaks were mainly family clusters (11/13) and imported cases from other provinces (9/13). Four outbreaks caused by transmission during the incubation period were observed. The incubation period, M ( P25, P75) was 5 (3.5, 7.5) d and the serial intervals, M ( P25, P75) was 5 (3.5, 11.5) d. For patients proactively seeking medical attention, 50% (13/26) had multiple visits at hospitals. The nucleic acid of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detected in 84.1% (37/44) of the cases between 2 days before and 7 days after disease onset. The overall secondary attack rate was 11.6% (29/249) while the rate in family was 32.1% (27/84). Conclusions:In the early stage of the COVID-19 epidemic in Haidian district, the outbreaks were mainly family clusters. Improving the ability in early identification of the cases, quarantine of close contacts and timely sample collection will assist controlling the epidemic from expanding.

On January 15, 2022, a 26 years old female (Case A) went to a sampling site for coronavirus disease 2019 (COVID-19) testing due to excessive fatigue and fever for two days. This patient preliminarily tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using a quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) method. Beijing CDC subsequently verified the result. Furthermore, a rapid site mutation test based on qRT-PCR showed that the virus carried the Q498R mutations but lacked the L452R, T478K, and P681R mutations (ABT, Beijing, China and Bojie), indicating the case was infected by the Omicron variant.;;In the following seven days, five close contacts tested positive in screening, including her mother (Case B), a colleague of the index case (Case C), and three family members of Case C (Case D, E, and F).

目的 对2017年1月—2018年12月北京市海淀区流行性感冒(流感)监测数据进行分析,了解海淀区流感的流行情况和趋势,为海淀区流感防控工作提供科学依据.方法 采集北京市海淀区国家级流感监测哨点医院2017—2018年的流感样病例咽拭子标本,采用实时荧光定量PCR方法进行流感病毒核酸检测.结果 2017—2018年共采集1743例咽拭子标本,检出流感病毒核酸阳性样本262例,阳性检出率为15.03％;2017年与2018年流感病毒核酸阳性检出率差异无统计学意义(P>0.05);男性流感病毒核酸阳性检出率高于女性(P<0.05);60岁及以上年龄组流感病毒核酸阳性检出率最高(P<0.05);冬、春季流感病毒核酸阳性检出率高于夏、秋季(P<0.05).结论 北京市海淀区在2017年与2018年流感流行强度较高,冬、春季为高峰季节,但2年流行的流感病毒优势株有所不同,老年病例流感病毒核酸阳性检出率最高,是流感防控重点人群,学校和托幼机构是聚集性疫情重点防控场所.

目的 对北京市海淀区某小学一起人类偏肺病毒感染疫情进行调查处置,分析流行特征和影响因素,为此类病毒感染疫情防控工作提供依据.方法 采用现场流行病学调查方法:对搜索病例进行个案调查,并采集病例咽拭子标本进行呼吸道多病原核酸检测.结果 该校共发生人类偏肺病毒感染16例,全部为学生,总体罹患率为38.10％ (16/42),不同性别罹患率差异无统计学意义(x2=2.041,P=0.153);核酸检测人类偏肺病毒阳性率为85.71％ (6/7),其他呼吸道多病原核酸检测均为阴性;病例集中在一年级(7)班,发病时间为11月29日-12月3日;潜伏期为2～4天;临床症状以发热、咳嗽为主,占100.00％和87.50％;发热时间最短3天,最长7天,平均(4.19±1.16)天.结论 人类偏肺病毒传染性强;潜伏期较短,约为2～4天;以发热、咳嗽为主要症状;发热期约为3.03 ～5.35天;没有特效治疗方法和疫苗.这些均使防控工作面临严峻的考验,亟需提高防控人员知识储备.

Objective:To analyze the regularity and epidemiological characteristics of clusters of fever cases in the 2018-2019 influenza season in Haidian district, Beijing.Methods:Field epidemiological survey method was used to carry out case investigation. Description and analysis of the data were performed.Results:A total of 62 clusters of fever cases were reported in Haidian district from October 2018 to April 2019. Among all the outbreaks, 88.71% (55/62) was caused by influenza viruse, 9.68% (6/62) by adenovirus, and 1.61% (1/62) by mycoplasma pneumoniae. The attack rate fluctuated between 5.08% to 62.86%, and the total attack rate was 29.07% (795/2735). The outbreaks occurred mainly in December 2018 and March 2019. Elementary schools were the main places where outbreaks occurred. The positive detection rate of throat swab samples was 72.04%. The dominant strain that caused clusters of fever cases from December 2018 to January 2019 was the influenza A(H3N2) virus, and the dominant strain was converted to type B/victoria-lineage influenza virus from March to April 2019. The clinical manifestations were mainly cough, sore throat and headache. No significant difference in morbidity was found between vaccinated and non-vaccinated students ( x2 = 3.74, P > 0.05). Conclusions:In influenza season, influenza virus was the main cause of clusters of fever cases in Haidian distract. The epidemics occurred mainly in schools, and elementary school students were the main harmed population. It is suggested that schools should take active measures for the influenza prevention and effectively campus disinfection and quarantine management.

目的 通过对2017年北京市海淀区67起诺如病毒聚集性疫情的流行病学特征描述和分析,找出潜在的危害因素,为切实有效预防疫情的发生和蔓延提供参考依据.方法 采取现场流行病学方法和描述分析方法,对疫情发生单位和疑似病例个案进行详细的调查,并进行统计学分析.结果 67起疫情中聚集性疫情57起,暴发疫情10起;67起疫情中诺如病毒GⅡ型65起,GⅠ和GⅡ混合感染型2起;报告疑似病例992例,波及人数5 701人,罹患率波动范围为4.1％～73.33％,平均罹患率为17.40％,2～6、7～12、13～18和19～60岁4个年龄组的呕吐、腹泻、恶心、腹痛和发热的症状比较,差异均有统计学意义(x呕吐=38.309,x2 腹泻=114.051,x恶心=55.445,x腹痛=106.129,x2发热=10.253;均P＜0.05);采集标本755件,检出阳性标本457件,检出率60.53％,不同类型的标本阳性率比较,差异有统计学意义(x2=234.271,P＜0.01).结论 作为诺如病毒感染疫情高发的中小学校和托幼机构,防控工作至关重要,在日常传染病防控中,一定要加强疑似病例的早期发现,及时隔离,防止疫情的蔓延;规范消毒,有效阻止病毒的快速传播;加强宣传教育,提高整体防病意识.