山丘型血吸虫病流行区小环境改造的费用-效果分析

EVALUATION OF COSTEFFECT OF SMALL ENVIRONMENT MANAGEMENT IN HILLY TYPE ENDEMIC REGIONS FOR SCHISTOSOMIASIS CONTROL

山丘型血吸虫病流行区因地制宜进行沟渠硬化、沼泽地改塘等小环境改造措施后，钉螺面积减少了６６．１６％，活螺密度、活螺框出现率分别下降了７６．５４％和７６．１３％，阳性螺密度下降了１００％；居民血吸虫病患病率略有下降，１４岁以下人群感染率为０，无急性感染发生。而实施药物灭螺的对照组９年来钉螺面积仅下降了２７．６２％，活螺密度及活螺框出现率分别上升了２６．３５％和１５１．０１％，是小环境改造点的９．８４倍和１１．１３倍，同时居民血吸虫病患病率较１９８７年上升了３７．４４％，１４岁以下人群感染率为１．２１％，并有零星急性感染病例发生。小环境改造一次性投资费用高于药物灭螺，但与农田水利相结合的小环境改造措施能够产生一定的间接经济效益，因此远期效果仍将优于药物灭螺。

In a hilly type endemic area, the environmental management measures against snail were taken to control schistosomiasis. The results showed that the snail areas reduced by 66.26%, density of snail, percentage of frames with living snail reduced by 76.54% and 76.13% respectively, density of positive snail reduced by 100%. The prevalence rate of schistosomiasis decreased slightly, no case among the population below 14 years old, and no acute schistosomiasis occured, which had highly significant difference compared with control area where only taken molluscacide measure. Although the first investment of environmental management was higher than that of molluscacide, but the cost for eliminating 100 m2 snail areas and cost of each person benefitted was 6.94 times and 11.39 times higher than that of molluscacide respectively, and it could also produce indirect economic benefit, the long term effect would still better.