中国2011-2014年发热伴血小板减少综合征流行特征分析

Epidemiological analysis on severe fever with thrombocytopenia syndrome under the national surveillance data from 2011 to 2014, China

目的 分析中国2011-2014年发热伴血小板减少综合征（SFTS）流行病学特征及其监测情况.方法 利用疾病监测信息管理系统的法定传染病报告数据分析SFTS三间分布和病例审核的及时性,收集突发公共卫生事件信息管理系统聚集性疫情资料分析其聚集性,采用 Cochran-Armitage趋势检验其随年龄变化的病死率,利用x2检验不同组别的病死率差异,检验水准取α=0.05.结果 2011-2014年23个省份共报告5 352例SFTS,其中16个省报告实验室诊断病例2 750例,占报告病例总数的51.4％,病死率约为7.9％,病例主要分布在河南、山东、湖北、安徽、辽宁、浙江、江苏7省,占全国病例总数的99.3％.4-10月为该病流行季,5-7月为疫情高峰.病例职业主要为农民（88.3％）.发病年龄主要集中在50-74岁,占病例总数的67.6％.病死率由40-44岁年龄组的3.7％逐步增加到≥80岁年龄组的13.5％.曾被误诊的病例其病死率高于其他病例（x2=12.726,P＜0.001）,0R=3.06（95％CI：1.61- 5.90）.聚集性疫情续发病例最可能的暴露因素是接触病例血液.结论 SFTS报告发病数呈逐年上升趋势.河南、湖北和安徽交界地区以及山东、辽宁发病例数较多,病例呈高度散发状态,5-7月为疫情高峰季,农民和中老年人是发病高危人群;偶有聚集性暴发疫情,且与接触病例或尸体血液相关;病例高龄和误诊是死亡的危险因素。

Objective To analyze the epidemiological features and surveillance management programs on severe fever with thrombocytopenia syndrome （SFTS） in China from 2011 to 2014.Methods The analysis of epidemiological characteristics and surveillance management programs was based on the annual reporting data collected from the National Disease Reporting Information System while the description of cluster incidents was based on those reports collected from the Public Health Emergency Information Management System （PHEIMS）.Association between age groups and fatality rate was tested under the Cochran-Armitage Trend Test.The difference of fatality rates between differing groups was analyzed,using the chi-square test,with statistical significance on α=0.05.Results Between 2011 and 2014,5 352 suspected,probable and lab-confirmed cases of SFTS were reported in 23 provinces,of which 16 provinces reported 2 750 lab-confirmed cases with a fatality of 7.9%,accounting for 51.4% of all the cases,nation-wide.Henan,Shandong,Hubei,Anhui,Liaoning,Zhejiang and Jiangsu reported 99.3% of those lab-confirmed cases.The period between April and October appeared the epidemic season,with its peak from May to July.Most cases were farmers,accounted for 88.3% of the lab-confirmed cases.People at the age between 50-74 occupied 67.6% of all the cases.Fatality of the disease continually increased from 3.7% in the age group 40-44 to 13.5% in the age group older than 80.Fatality rates appeared statistically different between the groups with or without misdiagnosis,with OR as 3.06 （95%CI：1.61-5.90）.Secondary cases of the cluster incidents were most likely to result from contacting the blood of the index cases.Conclusion Number of reported SFTS cases showed a rising trend in China.Henan,Hubei,Anhui,Shandong and Liaoning provinces appeared at high risk of the disease.Geographical distribution of the SFTS cases＇ seemed highly sporadic,with May to July being the peak season.Farmers and elderly were considered as high risk population.Occasionally,cluster incidents might be seen,as the result of contacting the blood of cases or corpses.Being at older age and misdiagnosis seemed to be risk factors for fatality.