2020年河南省信阳市新型冠状病毒肺炎密切接触者感染状况分析

目的 分析信阳市新型冠状病毒肺炎(COVID-19,简称新冠肺炎)密切接触者的感染率和危险因素,为制定疫情防控策略和措施提供科学依据.方法 收集信阳市2020年1月23日至3月2日报告的274例新冠肺炎确诊病例和无症状感染者的密切接触者的流行病学、临床和实验室检测资料,分析密切接触者不同类型的感染率和感染的危险因素.结...     

烟台市一起新型冠状病毒肺炎聚集疫情调查分析

目的 了解一起新型冠状病毒肺炎(简称新冠肺炎)聚集性疫情的传播特征和传播链,做好密切接触者的追踪和判定,为开展疫情防控提供参考. 方法 按照《新型冠状病毒肺炎防控方案(第四版)》开展现场流行病学调查,同时采集呼吸道标本开展新冠病毒核酸检测. 结果 该起聚集性疫情涉及病例12例,其中无症状感染者4例和确诊病例8例.确诊病...     

北京市新型冠状病毒肺炎本地确诊病例密切接触者的感染情况及危险因素分析

目的通过对北京市新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)本地确诊病例密切接触者中感染新型冠状病毒肺炎的病例或无症状感染者的感染率和危险因素进行分析,为本地新型冠状病毒肺炎密切接触者的精准管控提供科学依据。方法以2020年1月19日-5月31日北京市新型冠状病毒肺炎本地确诊病例的密切接触者为研究对象,共2 906人。采用χ~2检验比较感染率的组间差异,应用多因素Logistic回归分析密切接触者感染新型冠状病毒肺炎或无症状感染者的危险因素。结果 2 906名密切接触者中,166名转归为确诊病例或无症状感染者,总感染率为5.71%。单因素分析结果为女性(6.68%)感染率高于男性(4.71%);10岁(10.40%)和≥60岁(7.37%)年龄组、医院隔离(21.72%)、同住(15.37%)和同餐(7.11%)的密切接触者感染率较高。多因素Logistic回归分析显示,医务人员的感染风险较高(OR=2.26,95%CI:1.04～4.92),同住(OR=24.25,95%CI:10.44～56.32)和同餐(OR=10.54,95%CI:3.88～28.63)的感染风险较高,集中点隔离(OR=0.02,95%CI:0.01～0.03)和居家隔离(OR=0.09,95%CI:0.06～0.15)的感染风险较低。结论新冠肺炎密切接触者总感染率较高,同住和同餐的感染风险较高,应尽早排查密切接触者,并严格实施集中隔离的医学观察措施。     

内江市一起新型冠状病毒肺炎聚集性疫情流行病学分析

目的通过对内江市市中区首例新型冠状病毒肺炎病例引发聚集性疫情的调查分析,探讨其传播规律和流行特征。方法按照国家卫生健康委《新型冠状病毒感染的肺炎防控方案(第3版)》中的流行病学调查方案,通过查阅病历并结合现场流行病学调查,描述该事件发生发展及感染传播过程,分析疫情的流行病学特征。采集患者急性期呼吸道标本,采用Real-time RT-PCR方法检测新冠病毒核酸。结果市中区首例患者男性36岁,2020-01-29出现发热、干咳症状,鼻、咽拭子新冠病毒核酸检测阳性。在与患者接触的人员中共检出发现4例确诊病例,其余密切接触者目前未出现症状。结论该起疫情为内江市中区首例新冠肺炎病例引发的聚集性疫情,提示应加强对确诊病例和无症状感染者的密切接触者的早期新冠病毒核酸检测,同时增加对可疑病例的胸部影像学检查,减少误诊和漏诊。     

一起进口冷链食品相关的新冠肺炎聚集性疫情调查

目的 调查一起某冷链公司新型冠状病毒肺炎(简称新冠肺炎)疫情,分析其病例感染情况及疫情传播链.方法 天津市、区两级CDC专业人员组成疫情调查处置组,开展病例个案流行病学调查、工作及生活场所密切接触者及可能暴露阳性环境人员追踪排查;采集咽拭子、环境和进口冷链食品标本进行新型冠状病毒核酸检测.结果 筛检2549份咽拭子标本和749份环境样本,共发现2例新冠肺炎确诊病例和8份阳性环境标本.结论 这是一起因接触受新冠病毒污染的进口冷链食品引起的新冠肺聚集性疫情,提示应关注进口冷链食品作为载体的由"物-人"的新冠肺炎传播风险,加强冷链相关从业人员防护和日常环境清洁消毒.     

新型冠状病毒感染者居住环境用品核酸检测与分析

目的 对新冠肺炎患者确诊前的居住环境中密切接触物品开展新型冠状病毒核酸检测,评估传播风险。方法 选择2家经终末消毒72小时后的新冠病毒感染者居住场所,采集可能经口、手等密切接触的生活用品样本,采用实时荧光PCR方法检测新型冠状病毒核酸。结果 共采集生活场所样本41件,新型冠状病毒核酸（ORF 1ab靶标和N靶标）阳性5件,总阳性率为12.2%,其中患者1居家样本20件,阳性5件,阳性率25%;患者2居家样本21件均为阴性。结论 新冠肺炎患者在确诊前隔离居住期间的潜伏期,可通过密切接触等方式污染相关生活用品,具有导致共同生活成员感染风险,应加强对集中或居家隔离的新冠无症状感染者、密切接触者、出院返阳等高风险人员管理,做好病毒携带者和其他成员个人防护,对居住场所开展实时消毒和事后终末消毒,预防新冠持续传播。     

绵阳市三台县一起新型冠状病毒感染肺炎聚集性疫情调查分析

目的描述绵阳市三台县1起新型冠状病毒感染肺炎(简称新冠肺炎)聚集性疫情的流行病学特点,分析传播过程,总结有效措施,为此类聚集疫情调查与防控提供依据。方法依据《新型冠状病毒防控方案(第5版)》,应用现场流行病学的方法,对病例发病、诊疗、暴露史等情况进行调查,梳理出病例的密切接触者,并通过多部门协查机制,对密切接触者进行快速追踪与严格管理。结果2020-02,三台县报告1例新冠肺炎疑似病例。通过个案调查、环境卫生学调查与实验室检测,最终发现1例确诊病例,3例无症病原携带者和1例可疑阳性感染者,此外3份环境样品检测结果为阳性。结论通过此次疫情调查与处置,建议加大对新冠肺炎病毒无症状携带者的排查力度;对确诊、疑似病例以及无症状病毒携带者工作、生活环境开展终末消毒并进行效果评价;排查期间应增加疑似患者采样类型和次数,防止疑似阳性、无症状病毒携带者的漏诊;进一步规范病例筛查、消毒评价和疑似新冠肺炎病例监测等措施。     

群体免疫作为新型冠状病毒肺炎防控策略可行性分析

新型冠状病毒肺炎（新冠肺炎）具有传播快、防控难的特点。仅4个月时间，新冠肺炎快速传播到全球200多个国家或地区。中国采取了及早发现病例、确定密切接触者并实施14 d隔离医学观察、全国范围内倡导居家2周以上等围堵策略，成功地控制了新冠肺炎流行。英国曾一度采用群体免疫策略，让人群自然感染新冠肺炎，逐渐形成免疫屏障。本文分析了围堵与自然感染形成群体免疫两种策略在未来应对新冠肺炎疫情中的应用，并提出了平衡疫情防控与经济社会发展的常态化策略。     

新型冠状病毒疫苗对四川省部分地区新型冠状病毒奥密克戎变异株感染人群中的保护效果评价

目的 评价新型冠状病毒（简称新冠病毒）疫苗预防新冠病毒奥密克戎变异株感染所致发病、肺炎和重症的保护效果（Vaccine effectiveness,VE）。方法 采用病例-病例研究，对2022年2至7月四川省成都市和广安市报告的新冠病毒感染本土病例进行调查，分析新冠病毒疫苗预防奥密克戎变异株发病、肺炎和重症的VE以及经年龄、性别、基础性疾病调整后的VE(aVE,Adjusted vaccine effectivenes)，通过SPSS 21.0软件进行单因素和多因素Logistic回归分析，检验水准α=0.05。结果 本研究共纳入新冠病毒感染病例1 683例，均为新冠病毒奥密克戎变异株BA.2感染，临床结局为发病、肺炎和重症分别是511例（30.4%）、66例（3.9%）和11例（0.7%），重症人群中90.9%(10/11)都是60岁及以上老年人群。加强免疫预防奥密克戎变异株发病和肺炎的aVE分别是52.4%(95%CI:17.8%～72.4%)和81.6%(95%CI:60.0%～91.5%)，基础免疫预防肺炎的a VE是69.2%(95%CI:26.9%～87.0%)，未完成全程...     

宁波市新型冠状病毒肺炎密切接触者感染流行病学特征分析

目的 估算新型冠状病毒肺炎病例密切接触者的感染率,评估不同暴露状况下新型冠状病毒肺炎的发病风险。方法 采用前瞻性研究的方法,对新型冠状病毒肺炎病例和无症状感染者的密切接触者进行持续隔离医学观察,收集流行病学、临床表现和实验室检测资料,估算不同暴露下的密切接触者感染率。结果 宁波市新型冠状病毒肺炎发病流行曲线呈现持续的人传人特征。共追踪调查了2 147名密切接触者,总感染率为6.15%,确诊病例、无症状感染者的密切接触者感染率分别为6.30%和4.11%,差异无统计学意义（P>0.05）。不同关系的密切接触者中,以朋友/香客（22.31%）、家庭成员（18.01%）、亲戚（4.73%）感染较高率,医务人员密切接触者未发生感染,各密切接触者人群感染率差异有统计学意义（P<0.005）。与病例同住（13.26%）、乘坐同一个交通工具（11.91%）、聚餐娱乐（7.18%）均是感染高危因素。医院诊疗环境下的交叉感染也不容忽视（1.94%）。潜伏期中位数为5 d。结论 新型冠状病毒肺炎病例密切接触者的感染率高,需严格按照密切接触者管理方案实施隔离医学观察措施。     

上海市宝山区新型冠状病毒肺炎病例密切接触者感染危险因素分析

目的 探讨上海市宝山区新型冠状病毒肺炎病例密切接触者感染的危险因素,以期对后续的预防与控制提供依据。 方法 根据宝山区疾病预防控制中心现场流行病学调查和医学观察得到的疫情和密切接触者资料,通过单因素分析及二分类logistic回归模型多因素分析的方法,得出密接接触者感染的风险因素。 结果 2020年1月19日—5月31日,宝山区共管理确诊病例密切接触者885例,最终19例确诊为新型冠状病毒肺炎,感染率为2.15%。不同年龄组的密切接触者感染率差异有统计学意义(χ²=22.231,P＜0.001);与病例关系不同的密切接触者感染率差异有统计学意义(P＜0.001);与病例接触频率不同的密切接触者感染率差异有统计学意义(Fisher精确检验,P＜0.001);与病例接触地点不同的密切接触者感染率差异有统计学意义(Fisher精确检验,P＜0.001);与病例接触方式不同的密切接触者感染率差异有统计学意义(χ²=118.825,P＜0.001)。二分类logistic回归模型多因素分析显示:密切接触者与关联病例的接触方式为共同生活(OR=74.302,95%CI:16.694~330.697)、年龄增加(OR=2.112,95%CI:1.039~4.294)为其感染的危险因素。 结论 新冠肺炎病例的密切接触者管理过程中,与病例共同居住生活的、年龄高于60岁的密切接触者,为感染高危风险人群,需要重点防控。     

Epidemiology of SARS-CoV-2 among healthcare workers in North-Eastern Italy from March 1, 2020 to May 10, 2020

Background:During major epidemic outbreaks, the preparedness of public health systems is challenged and healthcare workers (HCWs) are at the frontline. Italy was among the first- and worst-hit countries by COVID-19.Aim:To analyze the prevalence and incidence of infection among HCWs in Friuli Venezia Giulia region (north-eastern Italy) from March 1 to the end of the Italian lock-down, May 10, 2020. Methods. HCWs exposed to COVID-19 patients were actively surveyed and all HCWs were routinely tested with nasopharyngeal and oropharyngeal swab for RNA virus detection (n. 54,670).Results:Infected HCWs (n. 595) represented the 32.3% of all COVID-19 cases in the region under 65 years of age, and incidence of infection was 11.4 cases/1000 workers. HCWs accounted for a significant proportion of coronavirus infection and experienced high infection incidence after unprotected contact. Conclusions. HCWs’ knowledge of SARS-CoV-2 epidemiology and proper infection control practices are critical to the control of the disease.     

“新十条”后医务人员新型冠状病毒感染管理、居家治疗及返岗建议

 2022年12月7日《关于进一步优化落实新冠肺炎疫情防控措施的通知》（简称"新十条"）提出各级医疗机构要保障正常医疗服务,为特殊患者提供就医便利。作为医疗救治及控制疫情蔓延的主力军,医务人员是感染新型冠状病毒的高危人群。医务人员感染新型冠状病毒后,采取正确的治疗、隔离措施,才能从根本上保障医务人员身体健康及生命安全,同时也是救治患者的有力保障。为此全国医院感染监控管理培训基地及中国感染控制杂志编辑部征求有关专家建议后,根据当前新冠肺炎疫情形势和新型冠状病毒变异情况,在参考国家文件、指南、权威文献的基础上,结合新冠疫情防控工作管理实践经验,特提出医务人员新型冠状病毒感染管理、居家治疗及返岗建议,以供有关医疗机构和医务人员参考。     

COVID-19 impact and vaccine effectiveness among healthcare workers of a large University Hospital in Lombardy,Italy

Background:Healthcare Workers (HCWs) are a key element in managing the COVID-19 pandemic, but they are also at high risk of infection.Objective:The aim of this study was to describe, in a large university hospital which provided healthcare services to patients with SARS-CoV-2 infection, the course of the epidemic among HCWs and effectiveness of COVID-19 vaccination in reducing SARS-CoV-2 infection and disease.Methods:Our case series included all “Fatebenefratelli Sacco” University Hospital workers. Data were collected until the 15th of May 2021 and analysed as part of the health surveillance program carried out by the Occupational Health Unit.Results:From March 2020 until May 2021, 14.4% of workers contracted COVID-19, with the highest incidence peak recorded during the second wave of the pandemic. The prevalence of infection was slightly higher in males than in females, and a greater number of cases was found in job categories characterized by direct patient care activities. We reported a higher prevalence of “serious/critical illness” in elder workers. A clear reduction of COVID-19 incidence was found in our population during the third pandemic wave, that coincided with the start of vaccination campaign.Discussion:HCWs have been at high risk of COVID-19 infection. Male sex and advanced age appear to be predisposing factor and negative prognostic factor respectively. An out-of-hospital setting appears to be the main source of COVID-19 confirming that the correct use of protective devices during work counters the risk of infection. Vaccination seems to reduce both documented cases of infection and severe illness.     

新型冠状病毒肺炎隔离病区医务人员职业风险与防控对策

 新型冠状病毒肺炎疫情对全球卫生安全造成强烈的冲击。隔离病区医护人员作为新型冠状病毒肺炎患者的直接接触者,职业损伤的危险因素包括生物、物理、化学和心理因素。如何做好隔离病区医务人员职业安全防护,使之有信心、有能力为患者实施及时有效的救治,成为医疗队亟待解决的问题。根据武汉疫区工作经验,本文对隔离病区医务人员职业损伤相关危险因素进行深入分析,建立了降阶梯式职业安全防护培训模式,设立个人防护用品指导岗位,制定职业暴露及躯体不适时的应急预案,旨在保障新冠肺炎隔离病区医护人员的职业安全,消除恐惧,增强工作信心。     

福建省新型冠状病毒肺炎患者密切接触者的流行病学特征与感染危险因素

  目的   探讨新型冠状病毒肺炎(coronavirus disease 2019, COVID-19)患者的密切接触者的流行病学特征和感染的危险因素。   方法   描述2020年福建省111名COVID-19患者的密切接触者特征, 以111名(102名确诊和9名无症状感染者)感染新型冠状病毒的密切接触者为病例组, 以未感染新型冠状病毒且资料完整的2 337名密切接触者为对照组, 采用Logistic回归分析模型探讨密切接触者感染的危险因素。   结果   111例中男性57名, 女性54名, 男女比为1.1:1, 年龄中位数为49.5岁, 密切接触者感染率为1.7%(111/6 718)。引起47起聚集性疫情, 占总起数88.7%(47/53), 占总病例数54.7%(162/296), 有7例潜伏期超过14 d, 最长达21 d, 1起聚集性疫情显示原代病例发病前2 d具有感染性。家庭续发率4.2%(73/1 739)、社区续发率为10.1%(24/237)、养老院续发率2.7%(7/256)、社交场所续发率为2.0%(4/199)、工作场所续发率3.0%(3/99), 续发率差异有统计学意义(χ2=20.76, P < 0.001)。确诊病例以轻型和普通型为主(88.2%), 临床严重程度与原代病例没有区别。最后接触到确定密切接触者时间中位数为2 d, 确定密切接触者到实施隔离时间为中位数1 d, 最后接触到发病时间中位数为7 d, 发病至就诊时间中位数为4.9 d, 就诊到确诊均在当天完成。多因素分析结果显示, 随着年龄的增大, 感染风险越大, 15~岁(OR=4.22, 95% CI:1.79~9. 96)和≥50岁(OR=6.61, 95% CI:2.77~15.78);接触频率时间越久, 受感染的机会越大, 一般接触(OR=3.58, 95% CI:1.70~7.54)和经常接触(OR=8.30, 95% CI:4.65~14.80);暴露于现症病例(OR=3.64, 95% CI:1.65~8.04)更易感染。   结论   新型冠状病毒续发率较高, 在2.0%以上; 感染新型冠状病毒的密切接触者临床严重程度与原代病例没有差别, 均以轻症为主, 年龄、接触频率和原代病例有无症状是其危险因素; 密切接触者协同追踪管理信息化程度不高, 成效不理想。     

Effectiveness of BNT162b2 vaccine against SARS-CoV-2 among healthcare workers

Background:The present study was aimed at evaluating the effectiveness of BNT162b2 among HCWs of a university hospital while a recrudescence of pandemics was hitting the province, with a high rate of the B.1.1.7 variant.Methods:The study was performed in the context of health surveillance at the workplaces. We monitored the SARS-CoV-2 infection and COVID-19 symptoms among HCWs classified by having received the entire vaccine schedule or not; the latter further classified in not vaccinated workers and workers who had received the first shot more than 14 days earlier. The SARS-CoV-2 infection was diagnosed by conventional RT-PCR on rhino-pharyngeal swabs, followed by gene sequencing in positive vaccinated HCWs. The cumulative incidence of infections in the period was normalised to 100,000 people.Results:At the end of the observation period, HCWs that had completed the full schedule were at lower infection risk than both unvaccinated HCWs and the workforce who had not yet gained the complete theoretical protection from the vaccine (by 2.4-folds). Overall, ninety-two SARS-CoV-2 infections were observed among HCWs, mostly among not protected workers (52 cases) but none of them showed symptoms requiring hospitalisation.Conclusions:The vaccination campaign effectively reduced the appearance of symptoms and the incidence of infections among vaccinated HCWs. Among vaccinated HCWs, gene sequencing was possible in five cases only, 4 B.1.1.7 and 1 B1.525 variants. The high rate of unsuccessful gene sequencing observed among infected vaccinated workers could be explained by a low viral burden. Vaccination for COVID-19 should be mandatory in occupational settings with a high infective risk.     

Protection of vaccination versus hybrid immunity against infection with COVID-19 Omicron variants among Health-Care Workers

Background aimThe Omicron COVID-19 variants BA.1* and BA.2* evade immune system leading to increased transmissibility and breakthrough infections. We aim to test the hypothesis that immunity achieved post COVID-19 infection combined with vaccination (hybrid immunity), is more effective against Omicron infection than vaccination alone in a health-care setting.MethodsData on regular pre-emptive PCR testing from all Health-Care Workers (HCWs) at Laiko University Hospital from 29th December 2020, date on which the national COVID-19 immunization program began in Greece, until 24th May 2022, were retrospectively collected and recorded. The infection rate was calculated after December 21st, 2021, when Omicron was the predominant circulating variant in Greece, as the total number of infections (positive PCR COVID-19 test regardless of symptoms) divided by the total person-months at risk.ResultsOf 1,305 vaccinated HCWs who were included in the analysis [median age of 47 (IQR: 36, 56) years, 66.7 % women], 13 % and 87 % had received 2 or 3 vaccine doses (full and booster vaccination), respectively. A COVID-19 infection had occurred in 135 of 1,305 of participants prior to Omicron predominance. Of those 135 HCWs with hybrid immunity only 13 (9.6 %) were re-infected. Of the 154 and 1,016 HCWs with full and booster vaccination-induced immunity, respectively, 71 (46.1 %, infection rate 13.4/100 person-months) and 448 (44.1 %, infection rate 12.2/100 person-months) were infected during the follow up period. No association between gender or age and COVID-19 infection was found and none of the participants had a severe infection or died.ConclusionsHybrid immunity confers higher protection by almost 5-fold compared to full or booster vaccination for COVID-19 infection with the Omicron variant among HCWs who are at high risk of exposure. This may inform public health policies on how to achieve optimal immunity in terms of the timing and mode of vaccination.