发热伴血小板减少综合征的流行病学特征及其与蜱密度消长的关系

Epidemiological characteristics of severe fever with thrombocytopenia syndrome and association with tick density

【目的】了解发热伴血小板减少综合征(SFTS)的流行特征,及其与蜱密度季节性消长的关系,为疾病防控提供相关依据。【方法】根据2013—2021年湖北省崇阳县SFTS疫情发生情况,采用布旗法调查草地蜱季节密度消长情况,分析疾病流行特征与蜱密度之间的关系。【结果】2013—2021年崇阳县共报告SFTS病例71例,年均报告发病率为1.88/10万,其中死亡8例。病例报告时间主要集中在6—8月份,占总数的61.97%。病例分布在11个乡镇41个行政村和4个城区,发病率最高的乡镇是路口镇(26例)和白霓镇(12例),2个乡镇发病数占报告总病例的53.52%。发病年龄主要集中在50~69岁,占报告总数的57.75%(41/71)。男女性别比为1.84∶1,职业大多数为农民。采集其中的41例病例急性期静脉血液进行病原学核酸检测,其中25例阳性,阳性率为60.98%。蜱密度和SFTS报告病例数之间呈正相关(r=0.78,P=0.003)。【结论】崇阳县游离蜱成蜱和若蜱的季节密度与SFTS的报告病例数之间存在一定相关性。

[Objective]To understand the epidemiological characteristics of severe fever with thrombocytopenia syndrome(SFTS),and the association with seasonal fluctuation in tick density,so as to provide scientific evidence for better control and prevention measures.[Methods]Descriptive epidemiological methods were used to analyze the SFTS epidemic situation in Chongyang County from 2013 to 2021.The cloth flag method was used to investigate the seasonal fluctuation in tick density and determine the association with the SFTS.[Results]A total of 71 SFTS cases were reported in Chongyang County from 2013 to 2021 including 8 deaths,with the annual morbidity rate of 1.88/10^(−5).The majority were mainly from June to August,accounting for 61.97%of the total reported cases.The cases were geographically distributed in 41 administrative villages and 4 urban areas in 11 towns.The highest incidence was in Lukou town(n=26)and Baini town(n=12),which accounted for 53.52%of the total reported cases.Furthermore,the cases were mainly 50‒69 years old,accounting for 57.75%of the total reported cases.The ratio of male to female was 1.84∶1,and most were farmers.Blood samples during acute phase in 41 cases were collected for examination of SFTS virus,of which 25 cases tested positive(60.98%).There was a positive association between tick density and the number of reported SFTS cases(r=0.78,P=0.003).[Conclusion]Seasonal density of free adult ticks and nymphs is associated with the number of reported SFTS cases in Chongyang County.