摘要
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。
Objectives To discuss the distribution of snails in marshlands and propose a suitable statistical method for schistosomiasis epidemiology survey. Methods Snail surveys were engaged twice in marshlands of Shangfan Lake, Jiangxi Province in spring season of 1997. The density of snail in arithmetic and log scales was calculated and normality of the snail distribution was discussed. Results The snail distribution in arithmetic scale in marshlands was not normally dis tributed. If snail data were transfered in the log scale, the density of snail was normal distribution. In that case, the standard deviation and coefficient variation (CV) were decreased, the value of skewness was closed to zero, and the value of Shapiro-Wilk normality lest was large enough to indi cate that data were a sample from a normal distribution in log scale. Conclusion The index of snail density in log scale will be better than that in arithmetic scale.
出处
《中国血吸虫病防治杂志》
CAS
CSCD
2000年第3期141-142,共2页
Chinese Journal of Schistosomiasis Control
