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目的以长沙市一起学校流行性腮腺炎暴发事件为例,分析流行性腮腺炎暴发的流行特征和传播能力,评价病例隔离、停课、疫苗接种在控制暴发疫情的效果。方法根据病例定义收集暴发事件中所有病例发病日期、隔离日期、返校日期、疫苗接种时间和接种剂次,以及学校停课时间和间隔,计算病例隔离比例、隔离效果指数、停课效果指数、疫苗接种的直接效果VE。采用离散时间模型模拟流行性腮腺炎传播特征以及模拟隔离和停课的效果,采用基于个体随机模型计算再生数R。结果整起暴发事件共发生8代病例,代间距为18 d。未接种疫苗的相对危险度RR=0.92(95%CI:0.48~1.76),VE=-0.08。未接种疫苗相对于接种1次、2次、3次的RR分别为0.93(95%CI:0.48~1.78)、0.94(95%CI:0.40~2.17)、0.42(95%CI:0.09~1.92),VE分别为-0.08、-0.06、-1.38。该起流行性腮腺炎暴发事件在小学部内部、初中部内部、初中部传播至小学部、小学部传播至初中部的R分别为4.35(95%CI:4.22~4.48)、1.11(95%CI:1.04~1.17)、0.03(95%CI:0.02~0.04)、0.06(95%CI:0.05~0.08)。采取所有病例隔离的措施,仅能将小学部的累计罹患率TAR由无干预时的97.80%降低为68.82%,将初中部由20.21%降低为4.20%。采取停课措施在小学部和初中部的效果均不显著,小学部的TAR均在90%以上,中学部的TAR均在10%以上。结论流行性腮腺炎在小学部的传播能力大于初中部,小学部和初中部内部的传播能力大于两个学部之间的传播能力。按照国家接种程序接种疫苗不能预防学校流行性腮腺炎暴发。所有病例隔离措施仅能起到一定的作用,但效果不理想。停课1周的效果更差。
Objective To analyze the epidemiological characteristics and dissemination capacity of mumps outbreak in a case of mumps outbreak in Changsha City and evaluate the effect of isolation, suspension and vaccination in controlling the outbreak. Methods The incidence date, isolation date, date of return to school, vaccination time and inoculation dose of all cases of outbreak were collected according to the case definition, and the time and interval of suspension of school were calculated. The percentage of isolation cases, isolation effect index, suspension effect index, vaccination The direct effect of VE. Discrete time model was used to simulate the characteristics of mumps transmission and the effects of simulated isolation and suspension classes. Regenerative numbers R were calculated based on individual stochastic model. Results The entire outbreak occurred a total of 8 generations of cases, the intergenerational distance was 18 d. The relative risk of unvaccination RR = 0.92 (95% CI: 0.48-1.76), VE = -0.08. The RR of unvaccinated against inoculation once, twice and three times were 0.93 (95% CI: 0.48-1.78), 0.94 (95% CI: 0.40-2.17) and 0.42 (95% CI: 0.09-1.92) , VE respectively -0.08, -0.06, -1.38. The outbreak of mumps was transmitted to primary and secondary schools from primary and secondary schools, respectively, with R of 4.35 (95% CI: 4.22-4.48) and 1.11 (95% CI : 1.04-1.17), 0.03 (95% CI: 0.02-0.04), and 0.06 (95% CI: 0.05-0.08). Taking all measures of case isolation, the cumulative TAR of primary school can only be reduced from 97.80% at non-intervention to 68.82% and from 20.21% at junior high school to 4.20%. The effect of adopting the suspension of classes was not significant in both primary and secondary schools, with TARs above 90% in primary schools and above 10% in TAR. Conclusions Mumps can spread more in the elementary school than in the junior middle school. The communicative ability of mumps in the elementary school and middle school is more than that in the two schools. Vaccination in accordance with the national vaccination program does not prevent school mumps outbreaks. All case isolation measures can only play a role, but the effect is not satisfactory. The effect of stopping for a week is even worse.