摘要：
Objective To investigate the changes of water level and the distribution of snails in Anhui province before and after runs of the Three Gorges Reservoir Project, and to determine the relationship between the two factors and schistosomiasis transmission. Methods The hydrologic data of Datong hydrologic station and the data of snail status and schistosomiasis morbidity in Anhui Province were collected. The data from 1991 to 2002 and 2003 to 2012 were considered as before and after the impoundment of the Three Gorges Reservoir Project. Based on the prevalence of schistosomiasis, the cases of people and cattle were speculated, and the average infection rate of people and cattle were calculated. The t⁃test was used to compare the difference of snail area and the density of living snails before and after the impoundment of the Three Gorges Project. The pearson method was used to analyze the relationship between water level and snail area. The spearman method was used to analyze the relationship between the water level and the distribution of snails. Results From 1991 to 2012, the range of the highest water level, the lowest water level, the difference between the highest and lowest water level, the mean in the abundant water seasons, the mean in the dry water seasons, and the difference between the abundant water seasons and the dry water seasons was 11.40-16.30,3.68-5.20,6.70-12.12,9.92-14.40,4.77-7.64 and 4.13-8.93 m, respectively. The snail areas was(28 613±362)hm2 and (29 477±918) hm2(t=-3.00,P=0.007), the density of living snails was 1.51(1.15-2.43)and 0.43(0.29-1.10)snails/0.11 m2(H=4.28,P<0.001)before and after the impoundment of the Three Gorges Project, respectively. The average infection rate of people and cattle was 1.68%(99 482/5 935 147)and 4.62%(13 923/3 011 33), and the average number of acute schistosomiasis cases was 328, before the impoundment of the Three Gorges Project; 0.60%(39 747/6 649 380), 1.65%(1 291/783 224)and 71 after the impoundment of the Three Gorges Reservoir Project, respectively. The snail areas had negative correlation with the highest water level, the difference between the highest and lowest water level, the mean in the abundant water seasons(r value was-0.514,-0.509 and-0.477; P value was 0.014,0.015 and 0.025, respectively). The infection rate of people had positive correlation with the highest water level, the difference between the highest and lowest water level, the mean in the abundant water seasons(r value was 0.532, 0.587 and 0.446; P value was 0.011,0.004 and 0.038, respectively).The infection rate of cattle had positive correlation with the highest water level, the difference between the highest and lowest water level(r value was 0.507 and 0.553; P value was 0.016 and 0.008, respectively).The number of acute schistosomiasis cases had positive correlation with the highest water level, the difference between the highest and lowest water level(r value was 0.481 and 0.486;P value was 0.023 and 0.022,respectively). Conclusion Following the runs of the Three Gorges Reservoir Project, the change of water level in the section of Anhui Province affected the distribution of snails and the infection of people and cattle to some extent. The snail areas showed an upward trend, and the density of living snails, the infection rate of people and cattle showed a downward trend. The runs of Three Gorges Reservoir Project has certain role to reduce flood and helpful for schistosomiasis control.%目的：分析三峡水利枢纽工程（三峡工程）蓄水前后安徽省钉螺分布和长江安徽段水位变化情况，以及二者与血吸虫病传播的相关性。方法收集1991—2012年长江安徽段大通水文站相关水文信息资料，以及同期安徽省血吸虫病病情和螺情资料。根据血吸虫病病情，分别推算全省血吸虫病病例数和病畜数，计算全省人群和家畜血吸虫平均感染率。比较三峡工程蓄水前（1991—2002年）后（2003—2012年）钉螺面积及钉螺密度的差异，分析长江安徽段水位与钉螺面积及血吸虫感染率的相关性。结果1991—2012年最高水位、最低水位、最高最低水位差、丰水期水位均值、枯水期水位均值和丰枯水位差值变化幅度分别为11.40~16.30、3.68~5.20、6.70~12.12、9.92~14.40、4.77~7.64和4.13~8.93 m。蓄水前、后全省钉螺面积分别为（28613±362）、（29477±918）hm2（t=-3.00，P=0.007），钉螺密度的P50（P25~P75）分别为1.51（1.15~2.43）、0.43（0.29~1.10）只/0.11 m2（H=4.28，P<0.001）。蓄水前全省人群和家畜的血吸虫平均感染率分别为1.68%（99482/5935147）和4.62%（13923/301133），人群平均急性感染例数为328例，蓄水后分别为0.60%（39747/6649380）和1.65%（1291/783224），人群平均急性感染例数为71例。钉螺面积与最高水位、最高和最低水位差值、丰水期水位均值均呈负相关（r值分别为-0.514、-0.509和-0.477，P值分别为0.014、0.015和0.025）；人群血吸虫感染率与最高水位、最高最低水位差值、丰水期水位均值均呈正相关（r值分别为0.532、0.587和0.446，P值分别为0.011、0.004和0.038）；家畜血吸虫感染率与最高水位、最高最低水位差值均呈正相关（r值分别为0.507和0.553，P值分别为0.016和0.008）；急性血吸虫感染例数与最高水位、最高最低水位均呈正相关（r值分别为0.481和0.486，P值分别为0.023和0.022）。结论三峡工程运行后，长江安徽段水位的变化对钉螺的分布以及人畜血吸虫感染产生一定影响，钉螺分布面积呈现上升趋势，钉螺密度、人群和家畜血吸虫感染率呈现下降趋势。三峡工程运行对长江安徽段具有一定的削洪作用，对控制血吸虫病流行起到积极作用。
