From treatment to prevention: reimagining schistosomiasis control through WASH and environmental management.

Abstract

Schistosomiasis remains a persistent global health challenge, primarily controlled through Mass Drug Administration (MDA) of praziquantel. While MDA has reduced prevalence and morbidity in endemic regions like China and Sierra Leone, its limitations, including rapid reinfection, logistical barriers to coverage, emerging drug resistance, and failure to interrupt transmission, highlight the inadequacy of a purely pharmacological approach. This review advocates for a paradigm shift from treatment-focused to prevention-oriented strategies, integrating Water, Sanitation, and Hygiene (WASH) interventions and environmental management with MDA. WASH interventions (safe water access, improved sanitation, hygiene education) reduce human contact with contaminated water and limit environmental egg contamination, cutting transmission pathways. Environmental management, particularly snail control via habitat modification, biological agents, and targeted mollusciciding, disrupts the parasite lifecycle by targeting intermediate hosts. Case studies from China, Rwanda, Brazil, and Zanzibar demonstrate the success of integrated approaches: China's multi-sectoral model combines chemotherapy with ecological modifications; Rwanda leverages WASH partnerships and community engagement; Brazil employs community-driven strategies; and Zanzibar's elimination efforts integrate snail control with behavioral change. Despite promising outcomes, implementation faces barriers: funding biases toward short-term MDA over sustainable WASH infrastructure, cultural resistance to behavioral change, and weak intersectoral coordination. The WHO's 2021-2030 NTD Roadmap underscores the need for cross-sector collaboration to address underlying determinants like poverty and infrastructure gaps. Eliminating schistosomiasis by 2030 requires reorienting global strategies toward holistic, equity-focused interventions combining 'pills, pipes, pits, and participation,' i.e. pharmacotherapy, water infrastructure, sanitation, and community agency, to achieve durable transmission interruption.