不同海拨对鹤庆县血吸虫病流行和控制的影响

目的了解不同海拔对云南省鹤庆县血吸虫病流行和控制的影响。方法收集鹤庆县全县及血吸虫病流行区基本情况、血吸虫病疫情、不同海拔地区自然植被分布情况并对资料进行分析。结果根据鹤庆县境内不同海拔地区自然植被的垂直分布规律,全县各行政村按海拔可分为2900～3953m、1800～2899m、1500～1799m、1500m以下4个地区,海拔>2900m地区没有血吸虫病流行,其余3个地区均有血吸虫病流行。血吸虫病疫情原来以海拔为1800～2900m的地区最为严重,流行村数、人口数、历史累计病人数、历史累计晚期血吸虫病(以下简称晚血)人数、历史累计钉螺面积占全县流行区比例分别为96.36%、97.57%、99.62%、100.00%、99.46%,1970年该地区血吸虫人群感染率为30.46%。2011年全县查出血吸虫病人数、晚血病例、血吸虫人群感染率、钉螺面积较历史累计病人数、历史累计晚血病人数、1970年血吸虫人群感染率、历史累计钉螺面积分别下降了99.99%、80.89%、99.99%、96.41%,没有发现感染性钉螺。2011年海拔1800～2900m的地区血吸虫人群感染率为0.003%,2011年现存晚血病例、查出病人全部分布在该地区,钉螺面积占全县钉螺面积的95.78%。2011年钉螺面积百分比以海拔<1500m的地区为高,有螺环境出现率、有螺框出现率、活螺平均密度、活螺最高密度均以海拔为1800～2900m的地区为高。结论研究不同海拔地区的自然植被分布对钉螺分布和控制、血吸虫病流行和控制的影响具有一定的实际意义。

The impact of distribution of altitude and natural vegetation on the prevalence and control of schistosomiasis in Heqing County

Objective To investigate the impact of altitude and natural vegetation on the prevalence and control of schistosomiasis in Heqing county.Methods The data concerning the prevalence of schistosomiasis,altitude and natural vegetation in Heqing county were collected and analyzed.Results Based the sea level all the villages in Heqing county could be divided into four different strata with altitudes of 2900m,1800-2899m,1500-1799m,and 1500m.There was no schistosomiasis in areas aobve sea level of 2900m,Formerly schistosomiasis was heavily prevalent in the areas with elevation of 1800-2900m,the number of prevalent villages,population,historically accumulated number of patients,historically accumulated number of advanced cases and the proportion of historically accumulated snail areas accounting for the total area of the Heqing county were 96.36%、97.57%、99.62%、100.00%、99.46%.The infection rate of schistosomiasis was 30.46% in 1970.The number of schistosomiasis cases detected,the quantity of advanced schistosomiasis patients,the infection rate of schistosomiasis in population in 1970 and total snails areas were decreased by 99.99%,80.89%,99.99% and 96.41% in the year of 2011 compared to that of historically recorded data.No infective snails were discovered.In 2011 the schistosomiasis infection rate in areas with elevation of 1800-2900 was 0.003% and all of the advanced schistosomiasis cases and schistosomiasis cases occurred in this area and 95.78% of snail areas in this county distributed in this area.The proportion of snail area was higher in areas with elevation of lower than 1500m,while the occurrence rate of snail,the rate with snails on obstacles in frame,the mean density of living snails,highest density of living snails were higher in areas with elevation of 1800-2900m.Conciusions It is of certain significance in investigation of the impact of distribution of altitude and natural vegetation on the distribution of snail and the prevalence and control of schistosomiasis in Heqing county.