Advancing WASH Interventions in Malaysia: A Systematic Review of Strategic Approaches, Behavioural Outcomes and Implementation Challenges

Objectives: Inadequate access to safe water, sanitation, and hygiene (WASH) continues to drive infectious diseases, malnutrition, and educational disparities, particularly among vulnerable populations. This systematic review examined WASH intervention strategies implemented in Malaysia between 2014 and 2025, focusing on shifts in hygiene-related knowledge, attitudes and practices (KAP), health outcomes, infrastructure improvements, and implementation challenges. Methods: A comprehensive search across five databases (Science Direct, PubMed, Scopus, Web of Science, and Google Scholar) identified twelve eligible studies targeting schools, healthcare settings, and rural or Indigenous communities. Results: Education-based interventions predominated (n = 10), often employing participatory and theory-driven approaches grounded in the Health Belief Model or Information–Motivation–Behavioural Skills framework. Evidence revealed significant improvements in KAP, particularly when digital, gamified, or storytelling elements were integrated. Community-led and caregiver-inclusive models demonstrated greater behavioural adoption and retention. Thematic analysis identified several implementation challenges, which include (i) sole reliance on self-reported outcomes with limited use of objective indicators, (ii) short intervention durations (<2 months) that limit long-term impact, and (iii) lack of policy and curriculum integration. Conclusions: Findings underscore the need for culturally tailored, longitudinal, and system-embedded interventions that combine behavioural theory with infrastructure investment. Integrating WASH initiatives into Malaysia’s health and education frameworks could advance Sustainable Development Goal 6, ensuring scalable and equitable improvements in hygiene literacy, community resilience, and public health outcomes.