湖沼地区水位变化对钉螺消长影响的广义相加模型研究  

Impact of the changing water level on the variance of Oncomelania hupensis populations in Lake Area with general additive model

作　　者：李源培[1] 何忠[1] 何明祯 姜杰 李君祥 周艺彪[1] 张志杰[1] 姜庆五[1] 

机构地区：[1]复旦大学公共卫生学院流行病学教研室,教育部公共卫生安全重点实验室,上海200032 [2]湖南省岳阳市君山区血防站

出　　处：《中华流行病学杂志》2010年第10期1148-1154,共7页Chinese Journal of Epidemiology

基　　金：基金项目：国家自然科学基金（30590374）;国家科技重大专项（2008ZX10004-011）;国家高技术研究发展计划（863计划）（2006AA022402）;上海市重点学科建设项目（B118）

摘　　要：目的 探索湖沼地区水位变化对钉螺消长的影响及其规律.方法 选择湖南省岳阳市长江村典型钉螺孳生地为现场,收集2001-2009年间的水位资料和螺情资料,包括平均水位、最高水位和最低水位及活螺密度、阳性螺密度、有螺框出现率和阳性螺框出现率等.描述水位指标和螺情指标的时间分布情况,用广义相加模型（GAM）拟合分析水位变化与钉螺消长之间的关系.结果 2001-2009年度中当年的平均水位和现场水淹天数对活螺密度的影响均有统计学意义（P＜0.01）,表现为二次曲线关系,活螺密度在平均水位为25.0m,水淹天数为120 d时最低.当年的平均水位和上一年的现场水淹天数对阳性螺密度和阳性螺框出现率的影响均有统计学意义（P＜0.05）,表现为二次曲线或三次及更复杂分段样曲线关系;对有螺框出现率的影响均有统计学意义（P值接近0.05）,表现为二次曲线关系.阳性螺密度和阳性螺框出现率在平均水位为25.0 m,上一年水淹天数为110 d时最低;而有螺框出现率在平均水位为25.0 m,上一年水淹天数为160 d时最低.结论 水位变化对钉螺消长的影响主要表现为非线性的光滑函数关系.水淹天数对有螺框出现率、阳性螺密度和阳性螺框出现率的影响存在滞后效应.用GAM拟合水位变化对钉螺消长的影响可能更贴近实际而便于解释,容易发现两者之间的潜在关系和规律.Objective To explore the impact and regularity of snail population after changing of water level and to develop effective control and prediction programs. Methods A typical snail habitat closed to Changjiang county in Yueyang city, Hunan province was selected as the survey field.Data on water level and the changing trend of snail population during 2001-2009 including the average water level, maximum and minimum water levels, snail and infected snail densities,proportion of sampling frames with living and infected snails etc. were collected. The distribution of water level and snail indexes were described and a general additive model（GAM）for the relationships between these indexes were also fitted. Results Impacts of the average water level and the watered-out days in current year in the surveyed field on the snail density were statistically significant（P〈0.01）, showing a quadratic curve association. The snail density remained at the lowest level when the average water level was at 25.0 m and the surveyed field watered-out days was 120. The average water level in current year and the field watered-out days in the past year showed statistically significant impacts on the infected snail density（P〈0.001）, the proportion of sampling frames with infected snails（P〈0.05）and living snails（P value neared 0.05）, presented a quadratic curve, a cubic curve or even a more complicated piecewise curve association. Both the infected snail density and the proportion of sampling frames with infected snails remained at the lowest level when the average water level was at 25.0 m and the watered-out days in the past year was 110, while the proportion of sampling frames with living snails kept the lowest level when the average water level was at 25.0 m and the watered-out days in the past year was 160. Conclusion The water level and the field watered-out days affected the development of snail population directly. The changing water level had an impact on snail population change, which mainly presented as nonli

关 键 词：钉螺 水位 广义相加模型 湖沼地区 

分 类 号：R184[医药卫生—流行病学]