Background. To estimate effect of COVID-19 control measures taken to mitigate community transmission in many regions, we analyzed data based on influenza surveillance system in Beijing from week 27th, 2014 to week 26th, 2020. Methods. We collected weekly number of influenza-like illness (ILI), weekly positive proportion of ILI and weekly ILI proportion in outpatients and the date of COVID-19 measures. We compared influenza activity indicators of influenza season 2019/2020 with preceding five seasons and built two ARIMAX models to estimate the effective of COVID-19 measures. Results. Compared with preceding five influenza seasons, ILIs, positive proportion of ILI, and duration of influenza epidemic period decreased from 13% to 54%, especially, the number of weeks from the peak to the end of influenza epidemic period, decreased from 12 to one. After natural decline considered, weekly ILIs decreased by 48.6% and weekly positive proportion dropped 15% in the second week after emergency response declared, and finally COVID-19 measures reduced 83%. Conclusions. We conclude public health emergency response can interrupt the transmission of influenza and other respiratory infectious diseases markedly. Keyword. COVID-19 control measures; influenza; ARIMAX

Objective:To estimate the vaccine effectiveness (VE) of the seasonal influenza vaccination in prevention of hospitalized severe acute respiratory infection (SARI) in Beijing in the 2018/2019 epidemic season of influenza.Methods:Hospitalized SARI cases in 11 Beijing hospitals during 2018/2019 epidemic season of influenza were selected as study subjects. Vaccination status was determined from registry record system. Influenza virus infection was detected by RT-PCR. A binary logistic regression model was used to adjust influence from age, time of onset and underlying diseases to calculate the odds ratio (OR) between influenza virus nucleic acid positive and negative groups. VE was then calculated by 1-OR.Results:The overall estimated VE was -42.6% (95% CI: -152.7% to 19.5%) while VE of 5-59 group was 58.5% (-119.4% to 92.2%).VE of vaccination within 60 days was 15.8% (-142.8% to 70.8%). Conclusions:The protection effectiveness of influenza vaccine for hospitalized SARI patients in Beijing during 2018/2019 epidemic season of influenza were limited. Vaccination coverage in target groups should be enhanced.

Flood disasters are the common public health emergencies,mainly leading to environmental damage,water pollution,food pollution,vector breeding,infectious disease epidemic and other risk factors of sanitary and anti-epidemic work.The guideline has been formulated with reference to the technical documents such as Guideline for Environmental Sanitation Disposal and Preven-tive Disinfection in Flooded Areas and Technical Proposal for Sanitary and Anti-epidemic Measures after Flood Disasters,as well as the latest research progress at home and abroad.In order to guide the sanitary and anti-epidemic measures in flooded areas,protect the health and safety of students and teachers and ensure the normal educational and teaching order,the guideline introduces the key measures that should be taken by schools,teachers and students in flood-striken areas.

Objective:To analyze the characteristics of coronavirus disease 2019 (COVID-19) cluster epidemic caused by Omicron variant BA2.2 in Market A of Beijing, so as to provide reference for future epidemic prevention and control.Methods:The data of COVID-19 cases in Market A of Beijing in 2022 were collected, and the epidemiological characteristics were analyzed. Respiratory tract specimens were collected for nucleic acid detection by real-time RT-PCR and sequencing analysis.Results:From April 30 to May 10, 2022, a total of 53 COVID-19 cases were reported, including 42 confirmed cases (79.2%) and 11 asymptomatic cases (20.8%). There were 33 male cases (62.3%) and 20 female cases (37.7%). The age ranged from 20 to 68 years old with a median age of 44 years old. The shortest incubation period was 3.2 days and the secondary attack rate was 33.3%.Conclusions:The epidemic situation in the market was affected by the speed of investigation for the index case. After the market is sealed and controlled, measures such as centralized isolation should be taken as soon as possible to avoid greater transmission risk.

Objective:To explore the association and the lag effect between meteorological factors and seasonal influenza activity in Beijing.Methods:Meteorological data and influenza surveillance data from 2014 to 2019 in Beijing were collected. Descriptive statistics were used to describe the data meteorological factors and influenza activity. A distributed lag non-linear model (DLNM) was used to analyze the relationship between influenza activity and meteorological factors.Results:From 2014 to 2019, there was a non-linear negative correlation between seasonal influenza activity and daily average temperature, relative humidity, and wind speed in Beijing. At -14.3 °C, the cumulative risk of daily average temperature was the highest ( RR=25.42, 95% CI: 11.84-54.57); At 8.0%, the cumulative risk of daily average relative humidity was the highest ( RR=36.61, 95% CI: 24.72-54.22); At 0.5 m/s, the cumulative risk of daily average wind speed was the highest ( RR=3.24, 95% CI: 1.75-6.00). Conclusions:The climate conditions of low temperature, low relative humidity, and low wind speed may be associated with the increased level of seasonal influenza activity in Beijing, which can increase the risk of influenza transmission.

目的 探索北京市猩红热发病的时空分布、演变特征及热点区域,为制定精准防控措施提供依据.方法 采用SaTScan软件进行时间扫描和时空扫描分析.利用R软件spdep包进行全局空间自相关分析以判断有无聚集,采用局部Getis-Ord(Gi*)进行热点分析,定位发病的局部聚集区域.结果 2015-2020年北京市猩红热发病率由西南到东北呈逐渐降低趋势.全局空间自相关分析显示,2015-2020年猩红热发病率存在空间聚集现象(Moran's I=0.406,P＜0.001),且为高-高聚集[Ci*=0.005,E(Gi*)=0.003].热点分析结果显示,10个区的48个乡、镇、街道为热点区域,主要分布于南部及西南部郊区,涉及区主要为大兴(12个)、房山(7个)和门头沟区(6个).时空分析显示,2017年4月-2019年1月北京市东南方向存在一个聚集区,2017年4月-2019年12月北京西南方向存在一个聚集区域.结论 2017-2019年北京市猩红热发病略有增加.丰台、房山、门头沟和大兴区等各区交界地应为北京市猩红热防控的重点地区,应在该区域重点人群中加强环境治理,并开展针对呼吸道传染病的预防措施及宣传教育.

What is already known about this topic? China has repeatedly contained multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks through a comprehensive set of targeted non-pharmaceutical interventions (NPIs). However, the effectiveness of such NPIs has not been systematically assessed. What is added by this report? A multilayer deployment of case isolation, contact tracing, targeted community lockdowns, and mobility restrictions could potentially contain outbreaks caused by the SARS-CoV-2 ancestral strain, without the requirement of city-wide lockdowns. Mass testing could further aid in the efficacy and speed of containment. What are the implications for public health practice? Pursuing containment in a timely fashion at the beginning of the pandemic, before the virus had the opportunity to spread and undergo extensive adaptive evolution, could help in averting an overall pandemic disease burden and be socioeconomically cost-effective.

Objective:To evaluate detection capability of pool testing and summarize characters of results by collecting the test results of pooled samples for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Beijing, so as to provide reference for the pool testing strategy for detection of SARS-CoV-2 and other infectious disease pathogens in the future.Methods:The positive pooled samples from November 3 to 17, 2022 were collected. the epidemiological investigation and laboratory test were applied for nucleic acid positive persons and the results were summarize and analyzed.Results:A total of 942 "10-in-1" pooled samples with positive results were collected with (0.98 ± 0.05) nucleic acid positive person detected in each sample. In the 812 pooled samples with positive detection of patient by individual sampling, the proportion of positive in open reading frame 1ab (ORF1ab) gene and nucleocapsid protein (N) gene with Ct ≥ 30 were 59.7% and 67.9% respectively. Among 923 infected persons, the proportions of Ct <30 for ORF1ab and N gene by individual sampling were 72.2% and 64.6%, respectively. The mean differences for ORF1ab and N genes between pooled and individual samples were 4.44±6.85 and 4.40±6.93, respectively. The spatial distribution showed that there was obvious aggregation in the distribution of infected persons tested by pooled and individual sampling.Conclusions:The pool testing strategy can effectively detect positive persons in practice. Applying the strategy may also effectively identify the spatial clustering and realize the role of early warning in the future testing for population.

目的 了解北京市幼儿园家长给儿童接种流感疫苗的意愿及其影响因素.方法 在北京市东城区和西城区分别随机选择4所幼儿园,将全部2 443名儿童的家长作为调查对象.于2016年1月4日-3月17日以自填方式对研究对象进行匿名问卷调查.主要调查内容为家长为儿童接种流感疫苗的意愿及相关因素.应用非条件多因素Logistic回归模型分析流感疫苗接种意愿的影响因素.结果 回收问卷2 055份,有效应答率为84.1％.分别有34.3％(697/2 030)和28.2％(570/2 018)的家长愿意给儿童接种免费、自费流感疫苗.非条件多因素Logistic回归分析显示,父亲接种(OR=6.975,P＜0.001)、认为儿童易感流感(OR=3.512,P＜0.001)、认为流感疫苗有效(OR=4.029,P＜0.001)、认为流感疫苗安全(OR=3.731,P＜0.001)和不担心流感疫苗副作用(OR=1.643,P=0.001)的家长给儿童免费接种流感疫苗的意愿更高;家庭月收入≥10 000 元(OR=1.340,P=0.019)、父亲接种(OR=3.074,P=0.001)、医务人员推荐(OR=1.383,P=0.012)、认为儿童易感流感(OR=5.019,P＜0.001)、认为流感疫苗有效(OR=4.532,P＜0.001)、认为流感疫苗安全(OR=2.750,P＜0.001)和不担心流感疫苗副作用(OR=1.910,P＜0.001)的家长给儿童自费接种流感疫苗的意愿更高.结论 当前北京市幼儿园家长给儿童接种流感疫苗的意愿较低,流感认知水平、医务人员推荐等因素影响接种意愿.

With COVID-19 public health control measures downgraded in China in January 2023, reported COVID-19 case numbers may underestimate the true numbers after the SARS-CoV-2 Omicron wave. Using a multiplier model based on our influenza surveillance system, we estimated that the overall incidence of SARS-CoV-2 infections was 392/100,000 population in Beijing during the 5 weeks following policy adjustment. No notable change occurred after the Spring Festival in early February. The multiplier model provides an opportunity for assessing the actual COVID-19 situation.

Prior to the emergence of the Omicron variant, many cities in China had been able to maintain a "Zero-COVID" policy. They were able to achieve this without blanket city-wide lockdown and through widespread testing and an extensive set of nonpharmaceutical interventions (NPIs), such as mask wearing, contact tracing, and social distancing. We wanted to examine the effectiveness of such a policy in containing SARS-CoV-2 in the early stage of the pandemic. Therefore, we developed a fully stochastic, spatially structured, agent-based model of SARS-CoV-2 ancestral strain and reconstructed the Beijing Xinfadi outbreak through computational simulations. We found that screening for symptoms and among high-risk populations served as methods to discover cryptic community transmission in the early stage of the outbreak. Effective contact tracing could greatly reduce transmission. Targeted community lockdown and temporal mobility restriction could slow down the spatial spread of the virus, with much less of the population being affected. Population-wide mass testing could further improve the speed at which the outbreak is contained. Our analysis suggests that the containment of SARS-CoV-2 ancestral strains was certainly possible. Outbreak suppression and containment at the beginning of the pandemic, before the virus had the opportunity to undergo extensive adaptive evolution with increasing fitness in the human population, could be much more cost-effective in averting the overall pandemic disease burden and socioeconomic cost.

Objective:To analyze the epidemiological characteristics of coronavirus disease 2019 (COVID-19) cases reported in Daxing district in 2020, so as to provide evidences for the further prevention and control of COVID-19 in Daxing district.Methods:Epidemiological investigation data of COVID-19 cases reported in Daxing district in 2020 were collected. The population, temporal and spatial distribution, sources of infection, time of onset, diagnosis and discharge of COVID-19 cases were analyzed by descriptive epidemiological methods.Results:From January 1 to December 31, 2020, 114 COVID-19 cases were reported in Daxing district, with a reported incidence of 6.14/100,000 and no death case. The male to female ratio was 1.07:1. The age of the cases was mainly between 20 to 60 years old (83.33%). In the district, 85% of towns/streets reported cases. According to the sources of infection, the epidemics can be divided into three stages, e. g, the epidemic caused by imported cases from Wuhan, the epidemic caused by imported cases from oversea, and the outbreak in Xinfadi wholesale market. There were 24 clustered outbreaks, and the family clusters accounted for 83.33%.Conclusions:The COVID-19 epidemics showed clear temporal clustering character and three stages of epidemics in Daxing district in 2020. Based on the epidemiological characteristics of each stage, the epidemics were timely controlled by precise prevention and control method.

Airborne transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the urgent need for aerosol monitoring of SARS-CoV-2 to prevent sporadic outbreaks of COVID-19. The inadequate sensitivity of conventional methods and the lack of an on-site detection system limited the practical SARS-CoV-2 monitoring of aerosols in public spaces. We have developed a novel SARS-CoV-2-in-aerosol monitoring system (SIAMs) which consists of multiple portable cyclone samplers for collecting aerosols from several venues and a sensitive "sample-to-answer" microsystem employing an integrated cartridge for the analysis of SARS-CoV-2 in aerosols (iCASA) near the sampling site. By seamlessly combining viral RNA extraction based on a chitosan-modified quartz filter and "in situ" tetra-primer recombinase polymerase amplification (tpRPA) into an inte-grated microfluidic cartridge, iCASA can provide an ultra-high sensitivity of 20 copies/mL, which is nearly one order of magnitude greater than that of the commercial kit, and a short turnaround time of 25 min. By testing various clinical samples of nasopharyngeal swabs, saliva, and exhaled breath condensates obtained from 23 COVID-19 patients, we demonstrate that the positive rate of our system was 3.3 times higher than those of the conventional method. Combining with multiple portable cyclone samplers, we detected 52.2% (12/23) of the aerosol samples, six times higher than that of the commercial kit, collected from the isolation wards of COVID-19 patients, demonstrating the excellent performance of our system for SARS-CoV-2-in-aerosol monitoring. We envision the broad application of our microsystem in aerosol monitoring for fighting the COVID-19 pandemic.

Objective:To understand the characteristics of hemagglutinin (HA) gene and antigenicity variation of influenza B Victoria lineage virus (BV) in Beijing in 2021, so as to provide scientific basis for influenza prevention and control in Beijing.Methods:The etiological surveillance results of influenza in Beijing from January to November 2021 were analyzed with statistical methods. Fifteen BV strains were randomly selected. The HA genes were amplified and sequenced. To analyze the gene mutation and evolutionary characters by hemagglutinin gene amplification and sequencing.Results:From January to November 2021, 16 097 samples of influenza like cases were collected. Two hundred and eight samples were positive by nucleic acid test. Two hundred and five samples were identified as BV (98.56%), and 3 samples were influenza B Yamagata lineage virus (1.44%). The similarity of nucleic acid and amino acid sequences between the 15 BV stains and the vaccine strain B/Washington/02/2019 were 98.39% - 98.75% and 97.86% - 98.40%, respectively. Phylogenetic analysis indicated that the 15 BV stains belonged to Clade1A.3a2. Multiple point mutations existed compared to the vaccine stain. There were 11 glycosylation sites in the 15 BV strains. One strains (6.6%) was a low response strain of the vaccine strain.Conclusions:BV strains were predominant among the influenza viruses observed in Beijing in 2021. HA gene loci showed multiple mutations, suggesting the importance of continuous surveillance of the mutations in this subtype for providing a scientific basis for influenza prevention and control strategies formulation.

新型冠状病毒肺炎疫情的暴发是对在当今新媒体环境下的突发公共卫生事件舆情管理及风险沟通的一次重大考验。因此有必要了解新媒体环境下的信息传播特点，突发公共卫生事件的舆情特征，新媒体在突发公共卫生事件传播中的双向作用，并探讨在当前新媒体环境下，如何综合运用新媒体传播方式合理有效开展突发公共卫生事件应急风险沟通。针对以上各部分，对新媒体时代的突发公共卫生事件舆情特征及风险沟通策略作一综述。

在全球新型冠状病毒肺炎（coronavirus disease 2019，COVID-19）持续肆虐的背景下，具备病毒载量高、传染性强、潜伏期短特征的新冠变异株，如Delta、Omicron变异株，使室内密闭空间的生物气溶胶传播机制研究成为防控呼吸道传染病疫情的热点。本文从生物气溶胶特性、采集与检测技术发展现状、生物气溶胶传播典型案例三方面总结国内外研究进展。

To estimate the effect of the corona virus disease 2019 (COVID-19) control measures taken to mitigate community transmission in many regions, we analyzed data from the influenza surveillance system in Beijing from week 27 of 2014 to week 26 of 2020. We collected weekly numbers of influenza-like illness (ILI) cases, weekly positive proportion of ILI cases, weekly ILI case proportion in outpatients, and the dates of implementation of COVID-19 measures. We compared the influenza activity indicators of the 2019/2020 season with the preceding five seasons and built two ARIMAX models to estimate the effectiveness of COVID-19 measures declared since January 24, 2020 by the emergency response. Based on the observed data, compared to the preceding five influenza seasons, ILIs, positive proportion of ILIs, and duration of the influenza epidemic period in 2019/2020 had increased from 13% to 54%; in particular, the number of weeks from the peak to the end of the influenza epidemic period had decreased from 12 to 1. According to ARIMAX model forecasting, after considering natural decline, weekly ILIs had decreased by 48.6%, weekly positive proportion had dropped by 15% in the second week after the emergency response was declared, and COVID-19 measures had reduced by 83%. We conclude that the public health emergency response can significantly interrupt the transmission of influenza.

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).

Objective:To understand the epidemic characteristics of influenza in Beijing from 2021 to 2022, so as to provide scientific basis for prevention and control of influenza.Methods:Weekly case numbers of influenza like illness (ILI) and aetiology surveillance data from level 2 and above hospitals were used to analyze the epidemic trend and pathogenic characteristics of influenza.Results:From 2021 to 2022, 530 829 ILI cases were reported and percentage of ILI was 1.25%. The influenza active period lasted for 15 weeks. The mainly group of ILI was 0-15 year old group (60.71%), and the proportion of people over 60 years old was 5.9%. The pharyngeal swab samples from 18 505 ILI cases were tested and the positive rate was 14.91%. The dominate influenza virus subtype was influenza virus B Victoria lineage (99.56%). Among the influenza virus B Victoria lineage, 44 specimens were in 1a.3a2 branch, showing a certain evolutionary distance to the vaccine strain B/Washington/02/2019 recommended by WHO this year.Conclusions:Enhanced surveillance and early warning of influenza and other respiratory infectious diseases, timely vaccination against influenza and adjusting disease prevention and control strategies would be essential.

目的 了解天津市第137例新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)确诊病例的疑似传染源(IgM抗体检出阳性,以下简称S)在京感染风险.方法 2020年6月23-24日,对S进行流行病学调查,收集其5月30日后在京活动史及其密切接触者,采集并检测S在京密切接触者的咽拭子和血样本,以及在京活动场所的外环境样本.结果 自5月30日,S三次来京看望其女友(下文简称G),主要活动场所为G住址,还涉及餐馆A、酒馆B、酒吧C等3处公共场所;共有密切接触者65人,其中G住址涉及女友1人、餐馆A涉及34人、酒馆B涉及21人、酒吧C涉及9人.采集全部65名密切接触者咽拭子样本和血样本进行新型冠状病毒核酸和抗体检测,结果均为阴性;采集4个活动场所96件外环境样本进行核酸检测,结果均为阴性.结论 基于S在京调查的证据,不支持S在京公共场所感染,S的血清IgM抗体阳性原因需进一步排查.