As intestinal infectious diseases are one major public health issue in China, there remains an urgent need to dynamically track the incidence trend and epidemiological characteristics of these diseases on the whole or by category.

To analyze the epidemiological characteristics, spatial distribution and clustering features of types A and B intestinal infectious diseases in China from 2008 to 2018, providing a theoretical basis for optimizing the prevention and control strategies of these two types of diseases.

Data on the incidence of types A and B intestinal infectious diseases〔including typhoid and paratyphoid, viral hepatitis (hepatitis A, hepatitis E and undifferentiated type of hepatitis) and dysentery〕in all regions of China (n=31, except for Hong Kong, Macao and Taiwan) from January 2008 to December 2018 were extracted in March 2022, using the Data-center China Public Health Science as the data source. The chi-square test for trend was used to examine the temporal trend of incidence of these two types of diseases. Descriptive epidemiology, spatial autocorrelation, and spatial and temporal clustering analysis were used to analyze the spatio-temporal epidemiological characteristics of the diseases, and to determine the key seasons and regions for epidemic prevention and control.

A cumulative total of 3 220 480 cases of types A and B intestinal infectious diseases were reported in China from 2008 to 2018, with an average annual incidence rate of 7.25/100 000, showing a decline in overall incidence rate (P<0.05) . The incidence rate of typhoid and paratyphoid, viral hepatitis and dysentery demonstrated a downward trend during the period (P<0.05) . The incidence rate of typhoid and paratyphoid decreased from 1.18 per 100 000 population in 2008 to 0.78 per 100 000 population in 2018. The incidence rate of viral hepatitis decreased from 9.81 per 100 000 population in 2008 to 4.34 per 100 000 population in 2018. The incidence rate of dysentery decreased from 23.65 per 100 000 population in 2008 to 6.56 per 100 000 population in 2018. Typhoid, paratyphoid and dysentery occurred more frequently in summer and autumn (from May to October) , while the incidence of viral hepatitis had no obvious changes across seasons. The spatial distribution map of types A and B intestinal infectious diseases in China indicated that, typhoid and paratyphoid had a high incidence rate in Yunnan, Guizhou and Guangxi in western China, viral hepatitis showed a high incidence rate in western China, and dysentery had a high incidence rate in Beijing and Tianjin. The spatial autocorrelation analysis showed that the incidence rate of typhoid and paratyphoid (except that in 2014) , viral hepatitis (except that in 2016) and dysentery in China over the years from 2008 to 2018 was spatially clustered (global Moran's I ranged from 0.09 to 0.24, P<0.05) . The spatial clustering of typhoid and paratyphoid and viral hepatitis was decreased first and then increased, and that of viral hepatitis declined first and then rose, but was weakened in general. The spatial clustering of dysentery was strong. The spatio-temporal scan statistics detected that Yunnan was the region with the highest incidence rate (the primary geographic cluster) of typhoid and paratyphoid during 2009 to 2013, nine regions with Tibet as the center had the highest incidence rate of viral hepatitis from 2008 to 2011, and Beijing and Tianjin were the regions with the highest incidence rate of dysentery from 2008 to 2012.

Having obvious spatial and temporal clustering characteristics, the incidence of types A and B intestinal infectious diseases in China decreased significantly during the period due to effective prevention and control. Our study may be used as a guide to identify key prevention and control areas and to develop prevention and control strategies according to the spatial clustering patterns of different intestinal infectious diseases.

肠道传染病是我国主要的公共卫生问题之一，动态追踪肠道传染病发病变化趋势和不同类型肠道传染病流行病学特征具有迫切性。

分析2008—2018年中国甲乙类肠道传染病的流行病学特点、空间分布及聚集性特征，为优化甲乙类肠道传染病的防控策略提供依据。

于2022年3月，从公共卫生科学数据中心提取2008年1月至2018年12月中国31省份（不含香港特别行政区、澳门特别行政区和台湾地区）甲乙类肠道传染病〔伤寒与副伤寒、病毒性肝炎（甲型、戊型和未分型肝炎）、痢疾〕的月发病例数和月发病率数据。采用趋势性χ²检验分析2008—2018年中国甲乙类肠道传染病发病率的变化趋势。采用描述性流行病学、空间自相关及时空聚集性分析方法对2008—2018年中国甲乙类肠道传染病的监测数据进行时空流行病学特征分析，确定疫情防控的关键季节和重点地区。

2008—2018年，全国累计报告甲乙类肠道传染病发病3 220 480例，甲乙类肠道传染病年均发病率为7.25/10⁵，发病率整体呈下降趋势（P<0.05）；伤寒与副伤寒、病毒性肝炎、痢疾发病率均呈下降趋势（P<0.05），伤寒与副伤寒发病率由2008年的1.18/10⁵降至2018年的0.78/10⁵，病毒性肝炎发病率由2008年的9.81/10⁵降至2018年的4.34/10⁵，痢疾发病率由2008年的23.65/10⁵降至2018年的6.56/10⁵。夏秋季（5—10月）为伤寒与副伤寒、痢疾的高发季节，病毒性肝炎发病无明显季节性规律。根据中国甲乙类肠道传染病发病率地图，西部地区的云南省、贵州省、广西壮族自治区为伤寒与副伤寒高发病率地区，病毒性肝炎高发区域主要集中在西部地区，北京市、天津市为痢疾的高发地区。全局空间自相关分析结果显示，除2014年的伤寒与副伤寒、2016年的病毒性肝炎外，2008—2018年中国历年伤寒与副伤寒、病毒性肝炎、痢疾发病均具有空间聚集性（全局Moran's I值为0.09~0.24，均P<0.05）；伤寒与副伤寒发病的空间聚集性先减弱后增强，病毒性肝炎发病的空间聚集性呈先下降后上升的趋势，但总体而言有所减弱，痢疾发病的空间聚集性较强。时空扫描统计分析结果显示，伤寒与副伤寒发病Ⅰ类聚集区域为云南省，聚集时间为2009—2013年；病毒性肝炎发病Ⅰ类聚集区域覆盖以西藏自治区为中心的9个省份，聚集时间为2008—2011年；痢疾发病Ⅰ类聚集区域为北京市和天津市，聚集时间为2008—2012年。

2008—2018年，中国甲乙类肠道传染病发病率明显下降，提示其预防控制效果显著；中国甲乙类肠道传染病发病具有明显的时空聚集性。可以以本研究结果为依据，确定防控重点区域，根据不同肠道传染病的空间聚集性特征，制定防控策略。