2015-2021年芜湖市输入性登革热病例流行病学特征及媒介伊蚊监测分析

Epidemiological characteristics of imported dengue fever cases and surveillance on vector Aedes from 2015-2021 in Wuhu City,Anhui Province

目的分析2015-2021年芜湖市输入性登革热病例流行病学特征,了解媒介伊蚊分布特点,为登革热风险评估和疫情防控提供科学依据.方法采用描述流行病学方法对输入性登革热病例资料进行流行病学特征分析;采用布雷图指数法对媒介伊蚊监测并收集数据统计分析.结果2015-2021年芜湖市共报告登革热病例12例,均为输入性病例;病例多集中在7-10月,共报告9例,占报告病例总数的75.0%;输入病例男性11例,女性1例,病例年龄集中在20~49岁组;东南亚国家输入11例,国内其它省输入1例.媒介伊蚊监测未发现埃及伊蚊;2015-2021年平均布雷图指数范围为9.5~19.1,其中每年的7-8月为平均布雷图指数较高期间(16.1~19.1),10月份平均布雷图指数最低(7.0);调查蚊幼的孳生地类型以闲置容器积水数量最多(2483处),占积水总数的57.1%;其孳生有伊蚊幼虫的阳性数也最多(448处),阳性率为18.0%.结论芜湖市输入性登革热病例以东南亚国家输入为主,输入时间和地点存在不确定性,2020-2021年受新冠肺炎疫情影响无输入性病例报告,主要媒介白纹伊蚊在芜湖市孳生地的类型多样、数量较多,每年7-8月白纹伊蚊平均密度较高,提示存在本土登革热疫情暴发的可能,今后需持续加强对输入性病例的监测和健全媒介伊蚊监测网络,适时开展疫情风险评估.

Objective To analyze the epidemiological characteristics of imported dengue fever cases in Wuhu City from 2015 to 2021,understand the distribution characteristics of vector Aedes,and provide scientific basis for dengue fever risk assessment and epidemic prevention and control.Methods Descriptive epidemiological methods were adopted to analyze the epidemiological characteristics of imported dengue fever cases,and Breitu index method to monitor vector Aedes and collect data for statistical analysis.Results From 2015 to 2021,a total of 12 dengue fever cases were reported in Wuhu City,all of which were imported cases;The cases were mostly concentrated from July to October,with a total of 9 reported cases,accounting for 75.0%of the total reported cases;There were 11 male and 1 female input cases,and cases concentrated in the age group of 20-49 years old;11 cases were imported from Southeast Asian countries,and 1 case was imported from other provinces in China.No Aedes aegypti were found during vector monitoring;The average Breitmap index range from 9.5 to 19.1,with July August being the period of high average Breit index(16.1 to 19.1)and October being the lowest average Breitmap index(7.0);The type of breeding ground for mosquito larvae surveyed showed the highest number of stagnant water in idle containers(2483 locations),accounting for 57.1%of the total amount of stagnant water;The highest number of positive cases(448)were found in the breeding of Aedes larvae,with a positive rate of 18.0%.Conclusion The imported dengue cases in Wuhu City are mainly imported from Southeast Asian countries,and the time and place of import are uncertain.There are no imported case reports affected by the COVID-19 in 2020-2021.The main vector Aedes albopictus has a variety of types and a large number of breeding places in Wuhu City.The average density of Aedes albopictus is high in July August every year,suggesting that there may be an outbreak of local dengue fever,In the future,it is necessary to continue to strengthen the monitoring of imported cases and improve the vector Aedes monitoring network,and timely carry out epidemic risk assessments.