西藏自治区亚东县自然疫源地特点及蚊虫和蜱虫空间分布特征

Characteristics of natural foci and spatial distribution of mosquitoes and ticks in Yadong County,Tibet Autonomous Region

目的:了解西藏自治区(简称西藏)亚东县自然疫源地特点及蚊虫、蜱虫的空间分布特征。方法:西藏亚东县自然疫源地生态地理特征、人口学信息、农牧业资料收集自亚东县2020年统计年鉴,媒介生物资料收集自亚东县疾病预防控制中心,2010-2021年亚东气象站数据收集自世界天气网站。2021年7月,根据亚东县植被、畜牧分布情况选择蚊虫、蜱虫采样点共20个进行现场调查。采用灯诱法诱集蚊虫,人工检查和布旗法捕捉蜱虫,分析蚊虫和蜱虫的空间分布特征。结果:西藏亚东县自然疫源地地势北高南低,海拔落差约5 000 m;水资源丰富,亚东河平均径流量为20.1 m 3/s;北部气候高寒干燥、南部温和湿润。2010-2021年亚东县年均站点气压为452.8 mmHg(1 mmHg = 0.133 kPa),月均最高气温、降水量及空气相对湿度分别为8.7℃、134.5 mm、81.3%,均在7月份。灯诱法共诱集双翅目昆虫6 897只,均为非吸血蚊虫;蚊虫总密度为163.77只/(灯·小时),优势种群为眼蕈蚊科,占89.69%(6 186/6 897)。不同采样地区中,以下亚东乡诱集蚊虫数最多,占67.17%(4 633/6 897);其他依次为亚东县县城和上亚东乡,分别占27.36%(1 887/6 897)、5.47%(377/6 897)。共对2 014只宿主动物进行体表检查,梳检出寄生蜱23只,包括硬蜱属20只、血蜱属3只;各蜱虫采样点均未捕捉到游离蜱。 结论:西藏亚东县自然疫源地气候和生态环境具有明显的垂直梯度;蚊虫和蜱虫有活动但密度不高,蚊虫密度整体呈南高北低的趋势。

Objective To learn about the characteristics of natural foci and the spatial distribution of mosquitoes and ticks in Yadong County,Tibet Autonomous Region(Tibet for short).Methods The eco-geographical characteristics,demographic information,agricultural and animal husbandry data of the natural foci in Yadong County,Tibet were collected from the Yadong County 2020 statistical yearbook,vector data were collected from the Yadong County Center for Disease Control and Prevention,and the data of the meteorological station in Yadong County from 2010 to 2021 were collected from the World Weather Network.In July 2021,a total of 20 mosquito and tick sampling points were selected for field investigation according to the distribution characteristics of vegetation and animal husbandry of Yadong County.The light trap method was used to trap mosquitoes,and the manual inspection and flag dragging method were used to catch ticks.The spatial distribution characteristics of mosquitoes and ticks were analyzed.Results The natural epidemic foci in Yadong County,Tibet,were high in the north and low in the south,with an elevation difference of about 5000 m.It was rich in water resources,and the average runoff of Yadong River was 20.1 m/s.The climate in the north was cold and dry,and the south was mild and humid.From 2010 to 2021,the annual average station air pressure in Yadong County was 452.8 mmHg(1 mmHg=0.133 kPa),the maximum monthly average temperature,precipitation and relative humidity of air were 8.7℃,134.5 mm and 81.3%,respectively,all in July.A total of 6897 diptera insects were attracted by the light trap method,all of which were non-blood-sucking mosquitoes.The total density was 163.77 pieces/(lamp-h),the dominant population was Muscaridae,accounting for 89.69%(6186/6897).In different sampling areas,Xiayadong Township collected the most mosquitoes,accounting for 67.17%(4633/6897);the others were Yadong County and Shangyadong Township,accounting for 27.36%(1887/6897)and 5.47%(377/6897),respectively.A total 2014 host animals were examined,and 23 parasitic ticks were caught,of which 20 were of the genus Ixodes and 3 were of the genus Haemophilus.No free ticks were caught in all ticks sampling points.Conclusions The climate and ecological environment of the natural foci in Yadong County,Tibet have obvious vertical gradient.Mosquitoes and ticks are active,but the density is not high,the density of mosquitoes is generally high in the south and low in the north.