无锡市某小学1起水痘暴发疫情的流行病学调查

目的 通过分析1起小学水痘暴发疫情的流行病学特征、影响因素,为制定有效防控水痘疫情的措施提供依据.方法 采用现场流行病学调查方法,确定病例定义,开展病例搜索,用描述性流行病学方法进行统计分析.结果 本起疫情共发生29例水痘病例,罹患率为1.75％,均为学生.病例分布在2个班级,班级内与首发病例相邻座位的学生(62.50...     

一起水痘暴发疫情调查及应急接种效果观察

目的了解某学校水痘疫情流行病学特征及水痘疫苗应急接种保护效果。方法采用描述流行病学方法分析流行病学特征,采用病例对照研究、分层分析等方法,探讨发病危险因素和疫苗保护效果。结果共搜索到水痘病例58例,罹患率为3.86%(58/1 503);该次疫情出现3次高峰,持续72天,病例分布在13个班级,涉及学生667人,班级病例数在1～14例,罹患率在1.85%～28.57%,各班罹患率差异有统计学意义(χ2=65.83,P<0.01),三年级病例占79.31%。病例对照研究发现,不良的洗手习惯、与水痘病例接触、未接种、接种史不详、接种间隔超过84个月均为发病危险因素(P值均<0.05)。突破病例19例,占32.76%,接种疫苗至发病间隔中位时间为85个月。接种疫苗组发病率为5.40%,未接种组为18.84%,疫苗保护率1剂次为71.30%,2剂次为100.00%。结论水痘疫情暴发后应尽早开展应急接种,且最好接种2剂次水痘疫苗。     

上海市某小学一起水痘暴发的流行病学调查

目的了解某小学水痘疫情流行特征,分析暴发原因,为防控小学水痘疫情提供参考。方法采用现场流行病学调查方法收集资料,用SPSS软件进行分析。结果该小学共2 393名学生,水痘疫苗接种率为82.37%。共发生21例水痘病例,学生罹患率为0.83%(21/2 393),持续47 d。有免疫史者罹患率为0.66%,无免疫史者为1.75%,差异有统计学意义(P=0.029)。结论水痘接种率较高的小学仍有水痘传播流行的可能。水痘疫苗能降低儿童患水痘风险,可考虑将其纳入国家扩大免疫规划,并积极开展水痘疫苗二剂次免疫程序实践。     

苏州工业园区1起小学水痘暴发疫情的调查及疫苗保护效果分析

目的 通过分析1起水痘暴发疫情,评价水痘减毒活疫苗保护效果,为学校疫情防控提供依据.方法 收集苏州工业园区某小学1起水痘突发公共卫生事件资料,进行流行病学分析,计算水痘罹患率、水痘疫苗接种率及疫苗保护率.结果 该起疫情共报告水痘病例64例,突破病例24例(占37.5％).病例主要集中在一年级(占73.4％);一年级水痘...     

杭州市3所小学风疹暴发和应急接种效果调查

对１９９６年杭州市３所小学的风疹暴发，和应急接种冻干风疹减毒活疫苗的效果进行了调查。结果显示：病儿风疹ＩｇＭ抗体检出率与采血时间密切相关，以出疹后５～２８天检出率最高（９７７３％）；风疹血凝抑制（ＨＩ）抗体临界滴度，显性感染为１∶１６，隐性感染为１∶２５６；抗体阴性的未接种疫苗者，经过风疹暴发，显性和隐性感染率分别辊为１３７９％、４４８３％，显性与隐性感染之比为１∶３６２５；暴发前抗体阳性率４０％，暴发后升至８８２４％，提示人群风疹抗体阳性率＞９０％可阻断风疹传播。抗体阴性者接种风疹疫苗后抗体全阳转，几何平均滴度倒数（ＧＭＲＴ）为２１８６９。风疹罹患率接种组和未种组分别为５８３％、２７６１％，疫苗保护率为７８８８％。     

大连市甘井子区某小学一起水痘暴发的调查分析

目的分析大连市甘井子区2015年某小学一起水痘暴发的原因和流行特征,为制定防控措施提供依据。方法采用描述性流行病学对水痘疫情资料进行分析。结果该小学共发生水痘68例,均为学生,罹患率为4.26%。疫情持续54 d,出现2次发病高峰。发病在6~12岁年龄组,其中10~11岁(43例,63.24%)。男生39例,罹患率4.52%(39/862),女生29例,罹患率3.95%(29/734),差异无统计学意义。接种水痘疫苗的学生罹患率26.86%(31/1 154),接种情况不详和无水痘免疫史的罹患率83.71%(37/442),差异有统计学意义(χ2=422.4,P0.01)。结论学校水痘暴发流行的危险性较高,建议学校等集体单位加强水痘疫情的监测,严格落实有效的控制措施,加强水痘疫苗的接种工作。     

商丘市某小学水痘暴发疫情调查分析

目的了解学校水痘暴发疫情的临床特征和流行病学特征,探讨发病原因,为科学防治水痘提供依据。方法应用描述流行病学分析方法对发病儿童进行调查分析。结果本次水痘暴发疫情累计发生23例,历时7 d,累及6个班级,罹患率0.95%,患者以低年级学生为主,通过采取控制措施,疫情得到有效控制。结论传染源未及时隔离、报告,造成持续传播是本次发病的危险因素。学校要严格落实传染病管理措施,执行传染病疫情报告制度、晨检和因病缺勤追踪制度,做好宣传教育工作。同时,卫生部门要做好传染病健康教育与促进工作,使儿童家长自觉为孩子接种水痘疫情,保护儿童健康。     

某小学一起水痘暴发疫情调查与处置

目的分析某小学水痘暴发疫情的流行病学特征及原因,为学校水痘疫情防控提供依据。方法采用现场流行病学方法对2016年中山市某小学的水痘疫情进行调查和分析。结果累计发生23例,罹患率为1.3%;2016年1月3日至8日共发生19例,达到发病高峰。疫情波及3个班,三(3)班罹患率高于其它2个班(χ2=34.250,P0.001)。首发病例未隔离、日常生活接触和疫苗接种年限长是本起疫情的主要危险因素。结论水痘疫苗接种率较高的小学仍可能发生水痘暴发疫情。建议调整水痘疫苗免疫程序为2剂,加强水痘疫情监测,及早做好暴发疫情处置。     

三门峡市某小学一起水痘暴发调查

目的明确2016年11月三门峡市某小学水痘暴发感染传播方式、波及范围并了解水痘疫苗在暴发中的保护效果;锻炼暴发调查处置能力。方法通过校医和班主任报告、查看学生因病缺课监测记录的方式进行病例搜索,对该校区出现的典型的水痘样皮疹者进行个案调查,并进行流行病学分析。结果共搜索到病例39例,全校罹患率为1.09%(39/3 571);暴发波及8个班级,较高罹患率分别为21.00%、16.90%和15.90%;流行曲线符合持续人传人模式;参加课外辅导班不是危险因素(x2=0.069,P=0.79);水痘病例接触史(x2=14.4,P<0.01,OR值为9.9,95%CI=2.8~35)与病例是玩伴(x2=4.98,P<0.05,OR值为4.0,95%CI=1.1~14)是危险因素。病例组和对照组水痘疫苗接种比例的差别(x2=0.93,P=0.33)差异没有统计学意义。结论首发病例未及时隔离治疗是造成本次暴发疫情的主要原因。     

北京市小学生水痘疫苗应急接种效果及影响因素评价

目的 评价北京市小学生水痘疫苗应急接种效果及其影响因素.方法 对2007年5-7月北京市4个区(县)49起小学水痘疫情应急接种进行前瞻性观察.将应急接种前发生水痘病例的班级和同楼层或同排平房无病例班级的全体7882名学生作为观察对象;收集水痘病史、疫苗接种史、病例个案等资料,采用描述流行病学方法评价水痘疫苗应急接种保护效果.结果 水痘疫苗应急接种总体保护率为85.26%.首例水痘病例既往有疫苗接种史、疫情发现及时、病例数少、距首例病例发病时间短的水痘疫苗应急接种保护效果较好;分别对水痘疫苗应急接种前已发生病例班级和同楼层或同排平房无病例班级的应急接种效果进行分析,疫苗保护率分别为84.26%和87.06%.首例病例既往有水痘疫苗接种史的应急接种保护率分别为92.09%和93.06%,均高于首例病例既往无疫苗接种史的学校.应急接种前仅发生1例病例的疫曲接种保护率分别为83.09%和93.02%,均高于应急接种前已发生2～3例病例的学校.首例病例发病后<5 d完成消毒、隔离和应急接种等综合措施的疫苗保护率分别为86.60%和92.73%,均高于首例病例发病后<5 d完成消毒、隔离、但≥5 d完成应急接种的学校.此外,学校教室为平房、无校车或食堂、无住宿、学生间无搭伴包车或就餐的学校应急接种后疫苗保护率较高.结论 北京市小学生水痘疫苗应急接种具有较高的保护率,有利于控制水痘疫情.     

1起水痘暴发疫情的流行病学调查

目的 通过分析1起学校水痘暴发疫情的特点、发病危险因素及水痘疫情的流行规律,为学校水痘疫情防控提供科学依据。方法 采用现场访问、现场查看、电话访问、传染病报表、因病缺课日志报表等流行病学方法对现有资料进行分析。结果 此次暴发疫情共发生水痘病例18例,总体罹患率为1.75%;疫情波及1个年级2个班级,各班罹患人数相等,男女生之间的罹患率差异无统计学意义;寄宿生与走读生罹患率统计学上有显著性差异。此次水痘疫情发生在秋冬季节,通风条件差,学生面临高考升学压力大,身体免疫力低,没有及时发现和隔离病人是发病的主要原因。结论 采取有效的防控措施,及时治疗隔离病人,提高易感人群的水痘免疫,加强晨、午检制度及传染病上报制度,加强水痘的健康教育,是学校水痘防控工作中的重点。     

Effectiveness of post-exposure prophylaxis during varicella outbreaks among primary and middle school students in Shanghai: An analysis of three-year surveillance data

ObjectivesTo evaluate the effectiveness of post-exposure prophylaxis conducted during varicella outbreaks among students in Shanghai.MethodsSurveillance data were collected from September 1, 2013 to December 31, 2016 involving 3524 susceptible students in 109 primary and middle school classes where emergency vaccinations (EVs) had been administered. Students were divided into two groups according to their prior vaccination (PV) varicella vaccine status. A secondary attack rate was used to compare EV and non-EV groups using a chi-squared test. Stratification analyses were performed, adjusting for the EV administration date, the vaccination coverage rate, and the number of cases prior to the EV.ResultsThe effectiveness rate was 92.2% (95% confidence interval (CI): 37.1–99.0%) when EV was applied within 3 days following the outbreak onset date, and 95.2% (95% CI: 79.9–98.8%) when vaccination coverage was ≥80% among students with PV. When students with PV received an EV for varicella within 3 days, the effectiveness rate was 100%.ConclusionsEV showed high protective effectiveness for varicella during outbreaks, especially if administered within 3 days of an outbreak and in conjunction with a high coverage rate.     

Vaccination against varicella as post-exposure prophylaxis in adults: A quantitative assessment

BackgroundVaricella can be severe in adults. When universal vaccination is not adopted, post-exposure prophylaxis has been recommended in adults with uncertain history of varicella to reduce the burden of the disease in adults, however its impact is not quantified.MethodsWe developed a Bayesian probabilistic framework to estimate the impact of post-exposure prophylaxis in adults. We hypothesized that post-exposure vaccination would be proposed only after varicella exposure in close relatives. Information regarding the nature of the culprit exposure was obtained from a sample of 221 adult varicella cases. The lifelong probability that adults aged 18 would be infected with varicella was determined using data from the French Sentinelles surveillance network. Estimates of post-exposure vaccination efficacy were then used to compute the number of cases and hospitalizations prevented in adults.ResultsFamilial exposure to varicella was reported by 81 adult cases out of 221. The probability of infection after exposure was 32%, so that six exposures on average were necessary to explain the observed cumulated lifetime incidence of varicella in non-immune 18 years old and over adults. Among the 35% of the 18 years old population with uncertain history of varicella, 11% would truly be non-immune. Post-exposure vaccination would prevent 26% of the cases (13 cases prevented per 100,000 adults per year) and 31% of the hospitalizations (0.2 hospitalizations prevented per 100,000 adults per year) if vaccination acceptance was 70%. An average of 16 adults would be vaccinated to avert one varicella case.ConclusionsPost-exposure vaccination is associated with a substantial decrease in the burden of the disease in adults in a country where universal vaccination is not recommended. This quantitative information may help inform professionals to uphold the recommendation.     

水痘疫苗在学校水痘暴发疫情中保护效果的病例对照研究

目的 评价接种1剂水痘疫苗在学校水痘暴发疫情中的保护效果(vaccine effectiveness, VE)。方法 采用1:2配对病例对照研究,收集中山市2013—2021年水痘暴发疫情调查资料,将病例数≥5例的班的所有病例（共942例）作为病例组,按1:2的比例选取同班、同年龄（±1岁）、同性别的1 884名健康儿童作为对照组,调查其水痘疫苗接种史,采用条件logistic回归分析水痘疫苗保护效果。结果 共调查3～14岁儿童2 826名,儿童接种1剂水痘疫苗的保护效果为58%（95%CI:50%～66%）,3～5岁、6～14岁儿童接种1剂水痘疫苗保护效果分别为75%（95%CI:62%～83%）和51%（95%CI:40%～61%）。儿童接种1剂后≤2年、3～5年、6～8年、≥9年的保护效果分别为78%（95%CI:66%～86%）、66%（95%CI:57%～74%）、51%（95%CI:36%～62%）、23%（95%CI:-11%～46%）。儿童接种1剂水痘疫苗的保护效果随接种后时间的延长而降低（趋势χ²=13.071,P<0.001）。结论 儿童接种1剂水痘疫苗有助于防控水痘暴发疫情,但其保护效果随接种后时间的延长而降低,难以阻断水痘传播。建议儿童及时接种2剂水痘疫苗,以预防学校水痘暴发疫情。     

A varicella outbreak in a school with high one-dose vaccination coverage, Beijing, China

Background

Varicella vaccine is available in the private sector in China, with a single dose currently recommended for children aged ≥12 months. We investigated a varicella outbreak in a school in Beijing with high varicella vaccination coverage to describe the outbreak, examine risk factors for vaccine failure, and calculate vaccine effectiveness.

Methods

A varicella case was defined as an acute generalized maculopapular rash without other apparent cause in a student without prior varicella attending the elementary school during August 30–December 28, 2010. Varicella among vaccinated students (breakthrough varicella) was defined as varicella occurring >42 days after vaccination. Students’ vaccination status was verified with immunization records and clinical presentations were collected from health care practitioners.

Results

Of the 951 students, 934 (98%) had no prior varicella history. Among these students, 916 had received 1 dose of varicella vaccine and 2 had received 2 doses (98% vaccination coverage) before the outbreak. A total of 87 cases occurred during the outbreak; most had breakthrough varicella (86/87, 99%) and mild disease (83/87, 95%). Age at vaccination (<15 months vs. ≥15 months) and time since vaccination before outbreak (<5 years vs. ≥5 years) were not associated with development of breakthrough varicella. Single-dose varicella vaccination was 89% effective in preventing any varicella and 99% in preventing moderate/severe varicella.

Conclusion

Single-dose varicella vaccination is highly effective in reducing varicella incidence and mitigating disease severity, but not high enough to prevent outbreak. A two-dose program might help to prevent varicella outbreaks in Beijing.     

遵义市1起小学暴发疫情水痘突破病例的临床特征和危险因素

目的分析1起小学暴发疫情水痘突破病例的临床特征和危险因素。方法对2019年贵州省遵义市一所小学水痘暴发疫情开展流行病学调查,分析水痘突破病例的临床特征;采用病例对照设计,分析水痘突破病例的危险因素。结果在该起暴发疫情中水痘突破病例占总病例的67.5%(27/40)。水痘突破病例与无水痘疫苗(VarV)免疫史水痘病例的发热比例分别为7.4%、38.5%(χ²=5.86,P=0.015),病程>7d比例分别为25.9%、61.5%(χ²=4.78,P=0.029),皮疹>50个比例分别为40.7%、84.6%(χ²=6.83,P=0.009)。VarV初次免疫后≥5年发生水痘突破病例的风险高(OR=5.01,95%CI:1.67-15.05),VarV初次免疫年龄≥15月龄、接种2剂次VarV的风险低(OR=0.33,95%CI:0.11-0.99;OR=0.10,95%CI:0.03-0.43)。结论水痘突破病例的临床表现不典型;接种2剂次VarV预防水痘突破病例的效果好,建议将2剂次VarV纳入国家免疫规划。     

Pox in the docks: varicella outbreak in an Australian prison system

OBJECTIVES: 1. Describe an outbreak of varicella in a prison system. 2. Highlight the risks of disease transmission within the prison environment. 3. Promote infection control guidelines for high-risk sub-groups within the prison system, including the application of quarantine. SETTING: Four prisons, one prison hospital, the prison transport system, one courthouse. MAIN OUTCOME MEASURES: Number of cases of varicella infection; reported varicella immunity status of cases and contacts; immunity status of known HIV antibody positive inmates. RESULTS: Five cases of chickenpox were identified. There were 23 contacts of the Index Case occurring during transport between prison and court and whilst being held in the court holding cells. Two of these contacts developed chickenpox despite having given a prior history of infection. There were over 300 inmates exposed to varicella zoster virus (VZV) during the outbreak, including one HIV antibody positive inmate who had serologically confirmed immunity. This inmate developed shingles following exposure to VZV from one of the cases. CONCLUSIONS: There is an elevated risk of respiratory transmission of infections such as chickenpox in prisons. Clear guidelines should be in place to protect HIV antibody positive people, pregnant women, and others who are at increased risk of complications from such infections. In the case of varicella, all inmates and staff without documented immunity should be screened to determine immunity, and if non-immune, should be offered VZV vaccination. Every effort should be made to prevent HIV antibody positive inmates being exposed to varicella, regardless of their varicella immunity status. If an HIV antibody positive inmate, who is known to be non-immune is exposed to varicella, Varicella Zoster immunoglobulin should be given within 96 h.     

南京市2018年某幼儿园一起水痘暴发疫情调查

目的分析南京市某幼儿园一起水痘疫情的罹患率，找出水痘暴发的危险因素，评价水痘疫苗的保护效果。 方法以2018年3月19日至6月27日南京市某幼儿园出现的54例水痘患者为研究对象，其中男性33例，女性21例；年龄3～25岁，其中幼儿年龄3～6岁，幼儿平均(5.30±0.88)岁。通过主动搜索和问卷调查的方法收集幼儿园学生和老师中水痘的发病情况，疫苗接种情况。 结果该起疫情共报告病例数54人，罹患率为7.74%，疫情涉及10个班级和2名老师，班级学生罹患率最高为34.3%。首例患者于2018年3月26日发病，疫情持续68 d。发病高峰时间为5月8日至22日。流行曲线提示为人传人模式。在该起暴发事件中，水痘疫苗的保护率为58%(RR＝0.42，95CI%：0.22～0.80)。 结论幼儿园等集体单位水痘暴发疫情的发生率较高，相关机构应该加强对学校、幼儿园等集体单位的传染病监测和管理，加强传染病相关知识培训。     

2014-2018年福建省水痘流行特征分析及趋势预测

目的 了解2014-2018年福建省水痘疫情流行情况并进行发病预测,为调整水痘防控策略提供依据.方法 收集福建省2014-2018年中国传染病报告信息管理系统的水痘病例资料及突发公共卫生事件管理信息系统的水痘突发事件报告资料,进行统计描述和分析.结果 福建省2014-2018年累计报告58 934例水痘病例,年均发病率...