甘肃省2004-2018年甲型肝炎时空聚集性分析

目的 分析2004-2018年甘肃省甲型肝炎（甲肝）时空分布与聚集性特征，为甲肝防控工作提供依据。方法 利用中国疾病预防控制信息系统传染病报告信息管理系统收集2004-2018年甘肃省各县（区）甲肝病例报告数据，描述甲肝疫情流行特征，采用SaTScan 9.1软件进行时空扫描分析、ArcGIS 10.3软件实现扫描结果可视化。结果 2004-2018年甘肃省甲肝年均报告发病率为10.91/10万，报告发病率呈现下降趋势，周期性和季节性均不明显；实施扩大国家免疫规划（EPI）后，年均报告发病率异常高值的7个县（区）位于临夏回族自治州和甘南藏族自治州；2004-2012年各年龄组发病RR值均低于0～9岁组（P=0.000）。除2015年0～9岁组外，2013-2018年各年龄组发病RR值低于≥60岁组（P=0.000）；年均报告发病率的趋势由北向南逐渐升高，由西向东逐渐升高；时空扫描结果显示：2004-2018年甘肃省甲肝发病存在时空聚集性。2004-2008年探测出1个一级聚集区，聚集半径为91.95 km，时间为2004-2005年，主要分布在临夏回族自治州和陇南市。2009-2018年探测出1个一级聚集区，聚集半径为183.26 km，时间为2009-2012年，主要分布在甘南藏族自治州、临夏回族自治州、定西市和陇南市。结论 2004-2018年甘肃省甲肝发病呈现显著的下降趋势，流行模式有了很大的变化，周期性和季节性均不明显。0～9岁组儿童甲肝报告发病率显著下降且低于其他年龄组，≥60岁人群发病率最高应被重点关注。甲肝存在时空聚集性，重点防控区域在甘肃省西南部地区。

Spatio-temporal clustering of hepatitis A in Gansu provice, 2004-2018

Objective To understand the characteristics of spatiotemporal clustering on hepatitis A in Gansu province and to provide evidence for hepatitis A prevention and control. Methods Data related to hepatitis A were retrieved from National Notifiable Disease Report System, ArcGIS 10.3 and SaTScan 9.1 in Gansu province from 2004 to 2018. Results The annual average report incidence rate of hepatitis A was 10.91/100 000, showing a descending trend with no periodic or seasonal features. After the implementation of national expanded immunization program, high annual incidence rates had been seen in Linxia Hui autonomous prefecture and Gannan Tibetan autonomous prefecture. From 2004 to 2012, the lowest RR value appeared in the 0-9 age group (P=0.000) while the highest RR value was in the over 60 age group during 2013-2018 except for the age 0-9 group in 2015. The annual average incidence rate was increasing from south to north and west to east, across the territory. Results from the temporal scanning program revealed that the incidence of hepatitis A was temporally aggregated from 2004 to 2018. For spatio-temporal scanning of 2004-2008, data showed one most likely cluster area (radius:91.95 km, Time frame:2004-2005), apparel mainly in Linxia and Longnan cities. Results from the spatio-temporal scanning program of 2009-2018 also showed that the most likely cluster areas (radius:183.26 km, Time frame:2009-2012) were in Gannan, Linxia, Dingxi and Longnan areas. Conclusions The reported incidence rates of hepatitis A were declining, without significant periodic or seasonal pattern in Gansu province from 2004 to 2018. In the 0-9 years-old group, the incidence rate showed the lowest, while the highest was in the 60 year-olds group. Spatio-temporal clustering of hepatitis A was observed in Gansu province from 2004 to 2018. Strategies on prevention and control of the disease should be targeted in the southwest regions of the province.