Kagabo Joseph, Tabo Zadoki, Kalinda Chester, Nyandwi Elias, Rujeni Nadine
College of Medicine and Health Sciences, School of Health Sciences, University of Rwanda, Kigali, Rwanda.
Centre for International Development and Environmental Research (ZEU), Justus Liebig University Giessen, Germany.
PLoS Negl Trop Dis. 2024 Dec 9;18(12):e0012730. doi: 10.1371/journal.pntd.0012730. eCollection 2024 Dec.
Schistosomiasis is an important snail-borne parasitic disease whose transmission is exacerbated by water resource management activities. In Rwanda, meeting the growing population's demand for food has led to wetlands reclamation for cultivation and increased agrochemical enrichment for crop production. However, the ecological consequences of agrochemical enrichment on schistosomiasis transmission remain unexplored.
A malacological survey was conducted in 71 villages selected from 15 schistosomiasis endemic districts. Snail sampling was done in wetlands used for agriculture, along lake Kivu and at constructed multipurpose water dams. Water physico-chemical parameters were collected at all snail sampling sites. Analysis of collected data was performed using Xgboost (gain) and Random Forest (mean decrease in accuracy), machine learning techniques, to construct models that evaluate and categorize the importance of all physico-chemical properties on the presence and abundance of intermediate host snails (IHS).
Different sets of parameters were relevant for the presence and abundance of Biomphalaria spp. and/or Bulinus spp. snails. Electrical conductivity, elevation, magnesium and lead content were deemed to shape the presence and abundance of Bulinus spp. snails. The impact of phosphate ion concentration, ammonia ions, total nitrogen and total organic carbon levels mirrored their importance towards the presence and abundance of Biomphalaria spp. Factors such as pH, electric conductivity, total nitrogen content and total organic carbon influenced the coexistence of both species. Our study highlights the value of integrating a wide range of predictor variables, enabling effective variable selection to uncover important predictors of snail distribution.
The results suggest that agrochemical compounds can enhance the abundance of IHS leading to an increased risk of Schistosoma transmission. Snail surveillance could therefore be integrated into agricultural expansion projects in our match towards schistosomiasis elimination. Recognizing the impact of agrochemicals on IHS is crucial for minimizing schistosomiasis transmission among those working in wetlands while meeting the growing need for food.
血吸虫病是一种重要的经蜗牛传播的寄生虫病，水资源管理活动会加剧其传播。在卢旺达，为满足不断增长的人口对食物的需求，湿地被开垦用于耕种，农业生产中农用化学品的使用也日益增加。然而，农用化学品富集对血吸虫病传播的生态影响仍未得到探索。
在从15个血吸虫病流行区选取的71个村庄进行了贝类学调查。在用于农业的湿地、基伍湖沿岸和人工建造的多用途水坝处采集蜗牛样本。在所有蜗牛采样点收集水的理化参数。使用Xgboost（增益）和随机森林（准确性平均下降）这两种机器学习技术对收集到的数据进行分析，以构建评估和分类所有理化性质对中间宿主蜗牛（IHS）的存在和丰度重要性的模型。
不同的参数集与双脐螺属和/或小泡螺属蜗牛的存在和丰度相关。电导率、海拔、镁和铅含量被认为影响小泡螺属蜗牛的存在和丰度。磷酸根离子浓度、铵离子、总氮和总有机碳水平对双脐螺属蜗牛的存在和丰度的影响反映了它们的重要性。pH值、电导率、总氮含量和总有机碳等因素影响了这两种蜗牛的共存。我们的研究强调了整合广泛预测变量的价值，能够有效地进行变量选择以发现蜗牛分布的重要预测因素。
结果表明，农用化学化合物可增加中间宿主蜗牛的丰度，导致血吸虫传播风险增加。因此，在我们消除血吸虫病的努力中，蜗牛监测可纳入农业扩张项目。认识到农用化学品对中间宿主蜗牛的影响对于在满足日益增长的食物需求的同时，尽量减少在湿地工作的人群中血吸虫病的传播至关重要。
