简介：血吸虫病是在在中国的中间降低的长江盆的一个严重公共健康问题。与微地理因素有关的蜗牛分发的空间变化的学习能帮助为重建的蜗牛消灭和环境选择恰当的措施。这篇论文学习了weights-of-evidence途径的理论建筑学。案例研究在中国在波伊昂·莱克区域的Waijiazhou沼泽地为在感染的蜗牛和地理因素联合的出现之间的空间关系被做。多，证据数据从地理因素联合来了在GIS穿过植被范围等级层，牛线路距离等级层，和特殊环境层(总共的181联合)的操作。重量对比索引的计算证明高植被范围，<45米的牛线路距离，和“地面消沉”有的特殊地理因素与感染的蜗牛的出现指导空间关系。由在GIS穿过操作的确认显示72.45%感染的蜗牛专注于积极重量对比索引的区域(从高度在重量对比索引的一份订单定序到低)，表明在发现建立的模型的高效率根据能明确地在学习区域被认出的地理因素联合感染了蜗牛。

简介：AbstractBackground:Due to sustained control activities, the prevalence of Schistosoma japonicum infection in humans, livestock and snails has decreased significantly in P. R. China, and the target has shifted from control to elimination according to the Outline of Healthy China 2030 Plan. Applying highly sensitive methods to explore the presence of S. japonicum infection in its intermediate host will benefit to assess the endemicity or verify the transmission interruption of schistosomiasis accurately. The aim of this study was to access the presence of S. japonicum infection by a loop-mediated isothermal amplification (LAMP) method through a 5-year longitudinal study in five lake provinces along the Yangtze River.Methods:Based on previous epidemiological data, about 260 villages with potential transmission risk of schistosomiasis were selected from endemic counties in five lake provinces along the Yangtze River annually from 2015 to 2019. Snail surveys were conducted in selected villages by systematic sampling method and/or environmental sampling method each year. All live snails collected from field were detected by microscopic dissection method, and then about one third of them were detected by LAMP method to assess the presence of S. japonicum infection with a single blind manner. The infection rate and nucleic acid positive rate of schistosomes in snails, as well as the indicators reflecting the snails’ distribution were calculated and analyzed. Fisher’s exact test was used to examine any change of positive rate of schistosomes in snails over time.Results:The 5-year survey covered 94,241 ha of environment with 33,897 ha of snail habitats detected accumulatively. Totally 145.3 ha new snail habitats and 524.4 ha re-emergent snail habitats were found during 2015-2019. The percentage of frames with snails decreased from 5.93% [45,152/761,492, 95% confidence intervals (CI): 5.88-5.98%] in 2015 to 5.25% (30,947/589,583, 95% CI: 5.19-5.31%) in 2019, while the mean density of living snails fluctuated but presented a downward trend generally from 0.20 snails/frame (155,622/761,492, 95% CI: 0.17-0.37) in 2015 to 0.13 snails/frame (76,144/589,583, 95% CI: 0.11-0.39) in 2019. A total of 555,393 live snails were collected, none of them was positive by dissection method. Totally 17 pooling snail samples were determined as positives by LAMP method among 8716 pooling samples with 174,822 of living snails, distributed in 12 villages of Hubei, Hunan, Jiangxi and Anhui provinces. The annual average positive rate was 0.41% (95% CI: 0.13-0.69%) in 2015, 0% in 2016, 0.36% (95% CI: 0.09-0.63%) in 2017, 0.05% (95% CI: 0-0.16%) in 2018, 0.05% (95% CI: 0-0.15%) in 2019, respectively, presenting a downward trend from 2015 to 2019 with statistical significance (χ2 = 11.64, P < 0.05).Conclusions:The results suggest that S. japonicum infection still persisted in nature along the Yangtze River and traditional techniques might underestimate the prevalence of schistosomiasis in its intermediate hosts. Exploring and integrating molecular techniques into national surveillance programme could improve the sensitivity of surveillance system and provide guidance on taking actions against schistosomiasis.