On the Role of Water Velocity in Schistosomiasis Transmission Via Progressive Wave Analysis

ABSTRACT In large river basins such as the Mekong, water velocity plays a crucial role in the transmission of schistosomiasis by transporting parasite larvae downstream, thereby extending the spatial reach of infection. Understanding how river flow shapes the spatial dynamics of disease transmission is essential for predicting reinfection risks and designing effective control strategies in hydrologically connected communities. This study presents a conceptual and theoretical framework for exploring the influence of water velocity on schistosomiasis spread. We formulate a spatially structured Ross–Macdonald‐type model that links human and snail infection prevalence through diffusion and advection processes. Analytical results show that infection can establish and propagate when the basic reproduction number exceeds one and the wave speed surpasses a critical threshold determined jointly by diffusion and flow velocity.