Gong Yanfeng, Zhang Shiqing, Lin Dandan, Cai Yu, Lv Shangbiao, Zheng Mao, Hu Benjiao, Lei Xiaolan, Xu Ning, Wang Jiamin, Huang Junhui, Zhou Yu, Zhu Liyun, Chen Yue, Jiang Qingwu, Li Shizhu, Zhou Yibiao
Fudan University School of Public Health, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
Key Laboratory of Public Health Safety, Ministry of Education, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
Parasit Vectors. 2025 Apr 26;18(1):156. doi: 10.1186/s13071-025-06782-3.
With the intensification of climate change and human engineering activities, environmental changes have affected schistosome-transmitting snails. This study explored the influence of environmental changes on the evolution of snail populations.
Data from annual snail surveys and related factors such as hydrology, temperature, vegetation, etc., on nine bottomlands from 1997 to 2022 were collected retrospectively from multiple sources. Interpretable machine learning and the Bayesian spatial-temporal model assessed the relationship between environmental change and snail density.
Between 1997 and 2003, mean snail density was in a high-level fluctuation stage. From 2003 to 2012, it declined significantly from 0.773/0.1 m to 0.093/0.1 m. However, it increased by 27.6% between 2013 (0.098/0.1 m) and 2022 (0.125/0.1 m). Since operation of the Three Gorges Dam (TGD) began in 2003, the duration of bottomland flooding decreased from 122 days (1997-2003) to 57 days (2003-2012) and then rebounded in 2012-2022, which was noticeable in the Anhui Section. The ground surface temperature and night light index of the bottomlands increased from 1997 to 2022. After adjusting for confounding factors (e.g. rainfall, temperature, and vegetation), the relative risk (RR) of increased snail density rose with flooding duration of between 20 and 100 days but decreased with flooding duration of > 100 days. Snail density showed an "L"-shaped relationship with the night light index, and the RR of increased snail density was lower at a higher night light index. Compared with bottomlands in the first quartile cluster of ground surface temperature, bottomlands in the second, third, and fourth quartile clusters of ground surface temperature had higher snail density RR values of 1.271 (95% CI 1.082-1.493), 1.302 (95% CI 1.146-1.480), and 1.278 (1.048, 1.559), respectively.
The TGD lowered the water level and flooding duration, which were not conducive to snail population growth. However, over time, the inhibitory effect of the TGD on snails may have been weakening, especially in areas far from the TGD. In recent years, the rebound of snail density may have been related to the rise in water levels and the change in the microenvironment. Establishing an efficient monitoring and response system is crucial for precisely controlling snails.
随着气候变化和人类工程活动的加剧，环境变化已对传播血吸虫的钉螺产生影响。本研究探讨了环境变化对钉螺种群演变的影响。
回顾性收集了1997年至2022年九个滩地年度钉螺调查数据以及水文、温度、植被等相关因素的数据，数据来源于多个渠道。采用可解释机器学习和贝叶斯时空模型评估环境变化与钉螺密度之间的关系。
1997年至2003年期间，钉螺平均密度处于高水平波动阶段。2003年至2012年，其密度从0.773/0.1平方米显著下降至0.093/0.1平方米。然而，2013年（0.098/0.1平方米）至2022年（0.125/0.1平方米）期间增加了27.6%。自三峡大坝于2003年开始运行以来，滩地淹没持续时间从1997 - 2003年的122天降至2003 - 2012年的57天，然后在2012 - 2022年有所反弹，这在安徽段较为明显。1997年至2022年，滩地的地表温度和夜光指数有所上升。在调整混杂因素（如降雨、温度和植被）后，钉螺密度增加的相对风险（RR）在淹没持续时间为20至100天之间时上升，但在淹没持续时间>100天时下降。钉螺密度与夜光指数呈“L”形关系，夜光指数较高时钉螺密度增加的RR较低。与地表温度第一四分位数聚类中的滩地相比，地表温度第二（RR值为1.271，95%置信区间1.082 - 1.493）、第三（RR值为1.302，95%置信区间1.146 - 1.480）和第四（RR值为1.278，95%置信区间1.048 - 1.559）四分位数聚类中的滩地钉螺密度RR值更高。
三峡大坝降低了水位和淹没持续时间，不利于钉螺种群增长。然而，随着时间推移，三峡大坝对钉螺的抑制作用可能在减弱，尤其是在远离三峡大坝的地区。近年来，钉螺密度的反弹可能与水位上升和微环境变化有关。建立高效的监测和应对系统对于精确控制钉螺至关重要。
