运用集中度和圆形分布法分析山东省威海市发热伴血小板减少综合征的季节性特征

Seasonal characteristics of severe fever with thrombocytopenia syndrome analyzed with concentration ratio and circular distribution method in Weihai,Shandong Province,China

目的分析山东省威海市发热伴血小板减少综合征(SFTS)的季节性分布规律,为制定有效的防控策略和措施提供科学依据。方法按月收集汇总2011-2022年中国疾病预防控制信息系统中报告的现住址为山东省威海市的SFTS病例数,运用集中度和圆形分布法在Excel 2007软件中通过编制计算公式分析山东省威海市SFTS的季节性分布特征。结果2011-2022年威海市累计报告SFTS病例1231例,年均报告发病率为4.01/10万,死亡率为0.37/10万,12年间发病率呈整体上升趋势(线性趋势χ^(2)=36.501,P<0.001)。山东省威海市SFTS的各月发病数集中度(M)值为0.66,具有较强的季节性。圆形分布集中趋势值r=0.654,平均角α=195.15°,角离差S=52.76°,雷氏检验Z=527.144,P<0.001,换算发病高峰日为7月17日,发病高峰期为5月25日-9月9日。结论山东省威海市SFTS整体上升的发病趋势应得到足够的防控重视,该病有较强的季节高发性,应在高峰期来临前尽早落实各项防控措施,减少重症和聚集性疫情的发生。

Objective To analyze the seasonal distribution of severe fever with thrombocytopenia syndrome(SFTS)in Weihai,Shandong Province,China,so as to provide scientific evidence for formulating prevention and control strategies for SFTS.Methods The monthly data on SFTS cases with registered addresses in Weihai during 2011 to 2022 were collected from the China Information System for Disease Control and Prevention.The seasonal characteristics of SFTS in Weihai were analyzed by using the concentration ratio and circular distribution method through creating formulas in Excel 2007.Results From 2011-2022,the total number of cases of SFTS in Weihai was 1231.The mean annual incidence was 4.01/100000,and the mortality rate was 0.37/100000.The incidence of SFTS showed a generally ascending trend during the 12 years(linearχ^(2)=36.501,P<0.001).The concentration ratio(M)of monthly numbers of SFTS cases in Weihai was 0.66,indicating strong seasonality.The circular distribution concentration trend(r)was 0.654,the angular mean(αˉ)was 195.15°,the angular deviation(S)was 52.76°,and the Z value for the Rayleigh test was 527.144(P<0.001).The predicted peak date was July 17,and the peak period was between May 25 and September 9.Conclusions The overall increasing incidence of SFTS in Weihai of Shandong Province deserves adequate attention to prevention and control.The strong seasonality of SFTS indicates that prevention and control strategies should be carried out prior to the peak period,so as to reduce severe cases and cluster outbreaks.The results provide a basis for scientific prevention and control of SFTS.