移动流行区间法在评估江苏省非伤寒沙门氏菌流行强度中的应用研究

Application of the moving epidemic method in evaluating the prevalence of non-typhoid Salmonella in Jiangsu Province

目的非伤寒沙门氏菌是食源性疾病的主要病原菌,其流行具有明显的季节性特征,通常在气温高时检出增加。但其在不同年份的流行持续时间、高峰时间和强度存在明显差异。因此,有必要建立非伤寒沙门氏菌的流行阈值和流行强度的评价方法,为监测预警服务。方法收集2015年1月至2019年12月江苏省食源性疾病病例监测系统中非伤寒沙门氏菌病例报告数据。应用移动流行区间法(moving epidemic method,MEM)利用2015—2018年的监测数据计算江苏省非伤寒沙门氏菌病例的流行周阈值,并评估2019年非伤寒沙门氏菌的流行强度。结果参数δ选值2.8,建立最优的MEM模型。江苏省非伤寒沙门菌病例数的流行开始周阈值为3.53,流行结束周阈值为5.44,中等流行强度周阈值为12.58,高等和极高流行强度周阈值分别为21.63和27.48。该模型在研究期间的合计灵敏度、特异度分别为0.936和0.725。结论将MEM方法应用于江苏省非伤寒沙门氏菌流行阈值的建立,具有较好的灵敏度和可接受的特异度。

Objective Non-typhoid Salmonella is the main pathogen of foodborne diseases,and its prevalence has obvious seasonal characteristics.The detection of non-typhoid Salmonella usually increases when the temperature is high.However,there are significant differences in the duration,peak time and intensity of the epidemic of non-typhoid Salmonella in different years.Therefore,it is necessary to establish an evaluation method for the epidemic threshold and epidemic intensity of non-typhoid Salmonella to serve monitoring and early warning.Methods The data of non-typhoid Salmonella cases reported in the foodborne disease surveillance system of Jiangsu Province from January 2015 to December 2019 were collected.The moving epidemic method(MEM)was used to calculate the weekly epidemic threshold of non-typhoid Salmonella cases in Jiangsu Province using the surveillance data from 2015 to 2018,and to evaluate the epidemic intensity of non-typhoid Salmonella in 2019.Results The parameterδwas selected as 2.8,and the optimal MEM model was established.The weekly thresholds of non-typhoid Salmonella cases in Jiangsu Province were 3.53 at the beginning of the epidemic and 5.44 at the end of the epidemic,while the weekly thresholds were 12.58 for the epidemic week with moderate epidemic intensity,and 21.63 and 27.48 for the epidemic periods with high and very high epidemic intensity,respectively.The combined sensitivity and specificity of the model during the study period were 0.936 and 0.725,respectively.Conclusion Using MEM method to establish the epidemic threshold of non-typhoid Salmonella in Jiangsu Province has good sensitivity and acceptable specificity.