浙江省学生其他感染性腹泻的时空聚集性分析

目的 探讨分析浙江省学生其他感染性腹泻(除霍乱、痢疾、伤寒和副伤寒)疫情的时空聚集性,比较不同参数设置下的探测效果,为更好的发现疫情提供参考.方法 采集2015年浙江省学生其他感染性腹泻病个案和县区人口数据,应用SaTScan按照不同最大扫描窗口对感染性腹泻疫情进行时空扫描分析.结果 2015年学生人群中其他感染性腹泻的病例共6 172例;学生病例数较多的市分别为宁波市(1572例,25.47％)、杭州市(1 327例,21.50％)、绍兴市(955例,15.47％).系统默认参数下时空扫描分析共发现阳性区域4个,一类聚集区1个,二类聚集区3个,其中发现疫情3起,1个为假阳性区域;按照最大扫描半径为35 km,最大扫描时间跨度为15d的参数设置,共发现阳性区域14个,一类聚集区1个,二类聚集区13个,其中发现疫情9起,5个为假阳性区域.两种模型假阳性率差别无统计学意义(P＞0.05).结论 学生感染性腹泻发病存在明显的聚集性,相对于默认参数情况下,缩小最大扫描窗口进行分析,能更为灵敏地发现小规模疫情.

Analysis on spatial and temporal clustering of the other infectious diarrhea among students in Zhejiang Province

Objective To discuss and analyze the spatial and temporal clustering of the other infectious diarrhea (except for cholera,dysentery,typhoid and paratyphoid) among students in Zhejiang Province,and compare the detection results based on different parameters,so as to provide reference for more effective epidemic identification.Methods The database was established by case information of other infectious diarrhea and the demographic data of all districts of Zhejiang in 2015.The spatial and temporal clustering of infectious diarrhea was analyzed by SaTScan based on different scanning windows in maximum.Results There were 6 172 cases of other infectious diarrhea in student group in 2015.The cities with more cases were Ningbo (1 572 cases,25.47％),Hangzhou (1 327 cases,21.50％) and Shaoxing (955 cases,15.47％),respectively.Based on the default scanning window,there were 4 positive clusters discovered including 1 most likely cluster and 3 secondary clusters.Three epidemics were identified and one epidemic was false positive.By defining 35 km as the maximum spatial cluster size and 15 days as the maximum temporal cluster size,there were 14 positive clusters discovered including 1 most likely cluster and 13 secondary clusters.Nine epidemics were identified and 5 were false positive.The false positive rates between the two models showed no statistical difference (P＞0.05).Conclusions Obvious spatial and temporal clustering of infectious diarrhea distribution is found among students in Zhejiang.Compared with the default parameters,narrow scanning window is more sensitive to find small scale epidemic.