日本血吸虫中间宿主-钉螺的螺口动力学研究

发布时间：2018-04-20 23:30

本文选题：血吸虫病 + 钉螺　；参考：《复旦大学》2009年硕士论文

【摘要】： 日本血吸虫病是一种严重危害人群健康的人兽共患寄生虫病,近几年疫情出现了反弹。钉螺是日本血吸虫的唯一中间宿主,是血吸虫病流行传播的关键环节;大型三峡水库的扩建、全球气候变暖等生态环境改变有可能引起钉螺的扩散从而形成新的流行区。钉螺生态学特别是螺口动力学可以为制定控制钉螺策略提供依据。本文动态观察新时期下钉螺种群螺口变化情况,内容涉及钉螺分布、微环境影响因素、种群密度和结构等方面。第一部分钉螺分布状态的动态分析目的探索钉螺分布的动态变化,为钉螺生态学及螺口动力学提供理论依据。方法在2007.10-2008.10选择湖南省岳阳市君山区洞庭湖的一块草滩及在2008.2～2009.2选择普格县城附近的一块“烂包”为现场,分别进行系统和随机抽样查螺,实验室压螺鉴定死活后分框计数。首先计算中位数、四分位间距及聚集度指标等进行统计描述,然后拟合负二项分布、对数正态分布,指数分布等不同的分布类型以探索不同时间点的钉螺分布状态。结果观察期间各月份钉螺的分布基本上为正偏态分布,湖南钉螺的中位数分别为7、9、1、0、3、4和1(只/0.01m~2),四川分别为6.5、4.5、3、4.0、4.0、4.0、4.0、2.0、11.0、3.O、1.0、1.0和2.0(只/0.01m~2);方差基本大于均数;聚集性指数随密度变化,变化方向两地不一。湖南水退初期10月份的钉螺数据对几种分布均不能较好拟合,11月份的钉螺分布呈对数正态分布,2008年4月份的钉螺分布同时符合负二项分布和指数分布,其它月份的钉螺分布均呈负二项分布;四川2008年6月份、10月份、12月份及2009年2月不符合负二项分布,其它连续型分布也不能有效拟合,其余月份符合负二项分布。结论钉螺分布不是单一的负二项分布,可能存在着与密度有关的一种动态变化,有待于提出新的、更广义的分布模型来更好地反映这种动态变化。第二部分钉螺分布微环境影响因素研究目的探索钉螺分布与微环境因素之间的关系,为生态灭螺、控制血吸虫病流行提供依据。方法现场选择及抽样同第一部分,查螺同时测量部分植被盖度、土表温度,并采集约30g土样。实验室压螺鉴定死活并分框记数、测量土壤含水量、土壤pH值。首先计算中位数、方差、最小值、最大值等指标描述钉螺及影响因素分布情况,然后绘制钉螺与影响因素间的散点图并做Spearman秩相关分析,最后拟合钉螺与因素间的单因素曲线模型、多因素广义相加模型。结果湖南共查104框,四川为75框。湖南pH值为4.7～7.92,四川为4.88～7.77:植被盖度湖南1%～96%,四川为1%～100%;土壤温度湖南为14.5℃～32.7℃,四川为19.3℃～27.1℃;土壤含水量湖南为0.07～2.00,四川为0.14～0.85。拟合钉螺与因素散点图发现两地趋势不同,Spearman秩相关分析多数显示无统计学意义。拟合钉螺密度与各因素间曲线模型,校正r~2均在0.9左右。多因素广义相加模型拟合发现湖区植被盖度没有统计学意义,其它因素两地均有统计学意义,在扣除线性及其它因素的影响下各微环境因素与钉螺间曲线关系表现与单因素拟合有所不同;两地因素对钉螺分布相对影响表现不同。结论湖南和四川钉螺与影响因素间关系不同,钉螺分布与因素间为平滑函数关系,不能简单采用负二项回归或其它线性回归模型拟合:两地应采取不同策略来改变钉螺生态,进而遏制钉螺的繁殖和扩散。第三部分钉螺种群生态观察目的探索自然生态环境下钉螺不同月份密度及新老构成等分布变化,为控制钉螺扩散和防治血吸虫病提供指导依据。方法现场选择及抽样方法同第一部分,测量钉螺体型、性别、死活等,分框计数;解剖钉螺生殖腺做电镜观察。绘制钉螺密度及死亡率曲线、钉螺体型分布图及雌雄分布图;分别采用身长≥5mm区分四川成螺、幼螺和螺旋5旋区分湖南成螺、幼螺,绘制不同时间成螺、幼螺分布图,描述生殖腺微观变化分布情况。结果湖南现场钉螺活螺密度整体趋于下降趋势,死亡率保持较高水平。幼螺全年基本存在,但比例保持较低比例,没有形成世代交替。雌雄构成无明显差异。生殖腺5月份卵巢较萎缩,8月份水下卵巢极度萎缩,雄性生殖腺变化不明显。电镜发现大雪冰冻天气和水淹下钉螺生殖腺有明显变化。四川钉螺钉螺密度动态波动,2008.10达到最高,此时出现较高比例幼螺并行成世代交替。死亡率保持较低水平,雌雄构成无明显差异。钉螺生殖腺5月份卵巢较丰满,8月份极度饱满,9月份开始萎缩,11月份生殖腺极度萎缩;电镜未发现生殖腺有明显变化。结论湖南持续大雪冰冻天气可能对钉螺生态有一定影响。钉螺密度整体趋于下降且没有形成新老交替。四川在10月份左右形成新老交替,钉螺种群呈动态平衡;微观电镜发现大雪冰冻天气及水淹对钉螺生殖腺有明显影响。鉴于不同生态结构,应采取相应策略开展灭螺措施以防止血吸虫病流行。
[Abstract]:Schistosomiasis is a kind of human zoonosis that seriously endangering the health of the population. The epidemic situation has rebounded in recent years. Oncomelania Snail is the only intermediate host of Schistosoma japonicum and the key link in the spread of schistosomiasis. The expansion of the large Three Gorges reservoir, the global warming and other ecological environment changes may cause the spread of Oncomelania snails. A new epidemic area was formed. The ecology of Oncomelania Snail ecology, especially the spiral mouth dynamics, could provide a basis for the formulation of the control strategy of Oncomelania snails. This paper dynamically observed the changes of the snails in the snail population under the new period, including the distribution of Oncomelania snails, the influence factors of microenvironment, the population density and structure.
The dynamic analysis of the distribution of Oncomelania hupensis in part 1
Objective to explore the dynamic distribution of Oncomelania hupensis and provide theoretical basis for the ecology and dynamics of snails.
Methods a "rotten bag" in the Dongting Lake of Junshan District, Yueyang, Hunan, and a "rotten bag" in the vicinity of pug county from 2008.2 to 2009.2 were selected as the site. The distribution of Oncomelania Snail Distribution at different time points was investigated by statistical description. The distribution of Oncomelania Snail Distribution at different time points was investigated by fitting negative two distribution, logarithmic normal distribution and exponential distribution. The distribution of Oncomelania snails was basically positive partial distribution during the observation period. The median of Oncomelania snails in Hunan were divided into 7,9,1,0,3,4 and 1 (only /0.01m~2), and 6.5 in Sichuan, respectively. 4.5,3,4.0,4.0,4.0,4.0,2.0,11.0,3.O, 1.0,1.0 and 2 (only /0.01m~2); the variance is basically greater than the average number; the aggregation index changes with the density, the change direction is different. The Oncomelania snails data in the early October of Hunan water retreat can not fit well. In November, the snail distribution is lognormal distribution, and the snail distribution in April 2008 is the same. According to the negative two distribution and index distribution, the distribution of Oncomelania snails in the other months showed negative two distribution; Sichuan in June 2008, October, December and February 2009 did not meet the negative two distribution, the other continuous distribution could not be fitted effectively, the rest of the month conformed to the negative two distribution. Conclusion the distribution of Oncomelania snails is not a single negative two distribution, possible. There is a dynamic change related to density. A new and more general distribution model is needed to better reflect this dynamic change.
The second part is about the factors affecting the distribution microenvironment of Oncomelania hupensis.
Objective to explore the relationship between the distribution of Oncomelania snails and microenvironmental factors, and to provide the basis for ecologically snail control and control of schistosomiasis epidemic. Method site selection and sampling are the same as the first part of the snail. In the same time, some vegetation coverage, soil surface temperature and 30g soil samples are measured at the same time. Value. First, calculate the median, variance, minimum value, maximum value and other indicators to describe the distribution of Oncomelania and influence factors, then draw the scatter plot between Oncomelania and influence factors and do Spearman rank correlation analysis. Finally, we fit the single factor curve model between Oncomelania and factors, and the multi factor generalized additive model in Hunan, and Sichuan is 75. Frame. Hunan pH value is 4.7 ~ 7.92, Sichuan is 4.88 ~ 7.77: vegetation coverage Hunan 1% ~ 96%, Sichuan is 1% to 100%; soil temperature in Hunan is 14.5 to 32.7, Sichuan is 19.3 C ~ 27.1, Hunan is 0.07 ~ 2 in soil water content, Sichuan as a fitting snails and factor scatter plot of Sichuan to 0.85. is different, Spearman rank correlation analysis Most showed no statistical significance. Fitting the density of Oncomelania snails with the curve model of each factor was about 0.9. The fitting of multi factor generalized additive model found that the vegetation coverage of the lake area was not statistically significant, the other factors were statistically significant, and the micro environmental factors and the snail curves under the influence of linear and other factors were deducted. The relationship performance is different from the single factor fitting; the two land factors have different influence on the distribution of Oncomelania snails. Conclusion the relationship between Oncomelania and Oncomelania hupensis in Hunan and Sichuan is different. The distribution of Oncomelania snails is a smooth function relationship between the distribution and factors of oncomelania, and it can not be simply fitted with negative two regression or other linear regression models: the two places should adopt different strategies to change The Oncomelania hupensis ecology will be changed to control the propagation and spread of snails.
Ecological observation of the third part of Oncomelania Snail population
Objective to explore the distribution changes of Oncomelania and new and old components of Oncomelania snails in natural ecological environment, and to provide guidance for controlling the spread of Oncomelania hupensis and preventing schistosomiasis. Method site selection and sampling methods were used in the first part to measure the size of Oncomelania snails, sex and death, and to dissect the reproductive gland of Oncomelania Snail. The curve of the degree and mortality, the distribution map of Oncomelania hupensis and the female and male distribution map, using the body length more than 5mm to distinguish the snail from Sichuan, the young snails and the spiral 5 swirl to distinguish Hunan into the snail and the young snail. The distribution diagram of the young snails at different time, the distribution of the young snails, and the distribution of the reproductive gland were described. The results showed that the living snail density in the Oncomelania snails tended to decline and died in Hunan. The percentage of young snail remained relatively high, but the proportion of young snail existed throughout the year, but the proportion remained low. There was no generation of generation alternation. There was no obvious difference between male and female. In May, the ovary of the gonadal gland was atrophy, the subaqueous ovary atrophied in August, and the male reproductive gland was not changed obviously. The electron microscope found that the freezing weather of heavy snow and the reproductive gland of the Oncomelania snails were obviously changed. Four The dynamic fluctuation of screw bolt density in Sichuan was highest in 2008.10. At this time, there was a higher proportion of young snails and generations alternately. The mortality remained low and the female and male composition had no significant difference. The Oncomelania gonanus gland was plump in May, August was extremely full, September began to atrophy, and the gonadal gland atrophied in November; the reproductive glands were not found in the electron microscope. It is obvious that the continuous heavy snow and freezing weather in Hunan may have a certain influence on the Oncomelania snails ecology. The density of Oncomelania snails tends to decline and does not form a new and old alternation. Sichuan formed a new old and old alternation in October, and the population of Oncomelania snails has a dynamic balance. Microscopic electron microscopy found that snow and freezing weather and water flooding have obvious influence on the reproductive gland of Oncomelania snails. Different ecological structure should adopt corresponding strategies to prevent snail epidemic.

【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R184

【参考文献】