2017—2019年北京市顺义区中小学校流行性感冒疫情特征分析

Epidemiological characteristics of influenza outbreaks in primary and secondary schools of Shunyi district of Beijing,2017—2019

目的对2017—2019年北京市顺义区中小学校流行性感冒(流感)流行季(10月1日—次年4月30日)流感疫情的特征进行分析,探讨流感疫情的影响因素。方法收集北京市顺义区2017年10月—2018年4月、2018年10月—2019年4月两个流感流行季的学校疫情资料,对疫情的规模、时间、病原体以及防控措施进行描述和分析。结果2017年10月至2019年4月,北京市顺义区报告中小学校流感疫情61起,其中聚集疫情占54.10%(33/61),暴发疫情占44.26%(27/61),突发疫情占1.64%(1/61)。2017—2018年流感流行季的21起疫情均发生在2017年第50周—次年第2周,2018—2019年流感流行季出现2个高峰,25起疫情发生在2018年第50周—次年第2周,13起疫情发生在2018年第13周—第18周;病原学监测结果以乙型流感病毒为主,共31起(占50.82%)疫情检出乙型流感病毒;乙型流感病毒疫情主要发生在小学1~3年级(93.55%,29/31)。干预措施中,疫情介入时间越早,疫情的规模越小(rs=0.986,P<0.01)。流感疫苗接种率与发病人数无相关性(rs=-0.145,P=0.108),2017—2018年和2018—2019年流感流行季流感疫苗的非病例接种率均高于病例接种率[73.99%vs 45.83%,45.94%vs 29.76%,OR(95%CI)=0.297(0.227~0.389)、0.499(0.403~0.616),P均=0.01)]。结论在学校流感疫情防控工作中,要提高流感疫苗接种率,同时加强学校对流感疫情监测的敏感性,当出现聚集的苗头时应及时进行报告,及早采取综合防控措施可以有效地减少流感暴发和突发疫情的出现。

Objective To explore the epidemiological characteristics of influenza outbreaks in primary and secondary schools of Shunyi district of Beijing.Methods Data of febrile outbreaks reported from 2017 to 2019 in Shunyi district of Beijing were collected.The epidemiological characteristics were described and analyzed by scales,time,pathogens and interventions of the outbreaks.Results A total of 61 influenza epidemics in primary and secondary schools were reported with the aggregate at 54.10%(33/61),the proportion of outbreaks was 44.26%(27/61)and public health emergencies at 1.64%(1/61).The 21 influenza epidemics during 2017 and 2018 flu seasons occurred in the 50 th week of 2017 to the 2 nd week of the following year,with 2 peaks in the 2018—2019 flu seasons and 25 influenza epidemics in the 50 th week of 2018 to the 2 nd week of the following year.The results of pathogen monitoring were mainly influenza B virus(50.82%,31/61);influenza B virus mainly occurs in grades 1-3 of primary school(93.55%,29/31).In the intervention study,the earlier of the epidemic intervention,the smaller of the epidemics(rs=0.986,P<0.01).No significant correlation was found between influenza vaccination rate and number of cases(rs=-0.145,P=0.108),the rate of vaccination in non-case was higher than that of cases(73.99%vs 45.83%,45.93%vs 29.76%),with OR(95%CI)=0.297(0.227-0.389),0.499(0.403-0.616),P=0.01.Conclusions To prevent and control influenza epidemics in schools,vaccination and surveillance of influenza should be strengthened.