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目的对湖滩钉螺分布的正态性进行讨论，提出适当的统计学方法供血吸虫病流行病学调查参考。方法 １９９７年３月 １０日和４月１６日连续两次调查钉螺，计算框内活螺数，对其分布特性进行统计处理。结果本次调查显示每框活螺数不符合正态分布，对其观察值进行对数转换后，其标准差小于均数，偏峰值减小，几何均值与中位数接近，经 Ｓｈａｐｉｒｏ－ｗｉｌｋ检验，对数转换后的数据符合正态分布。结论在计算活螺密度时，应将观察值进行对数转换，以几何活螺密度表示。
Objective To discuss the normality of distribution of Oncomelania huppuga on the beach and put forward the appropriate statistical method for the reference of epidemiological investigation of schistosomiasis. Methods Oncomelania was investigated twice in succession on March 10, 1997 and April 16, 1997. The number of living snails in the box was calculated and their distribution characteristics were statistically analyzed. Results The survey showed that the number of live snails per box did not fit the normal distribution. After logarithmic conversion, the standard deviation was less than the mean, the partial peak was decreased, and the geometric mean was close to the median. After Shapiro-wilk Test, logarithmic converted data in line with the normal distribution. Conclusions In calculating live lobe density, the observed values should be logarithmically transformed, expressed as geometric live lobe density.