Background: Environmental hygiene and sanitation remain foundational pillars in the global effort to control and prevent infectious diseases. Inadequate sanitation and poor hygiene practices continue to drive preventable morbidity and mortality, particularly in low- and middle-income countries (LMICs). Objective: This review examines the mechanisms through which environmental hygiene and sanitation influence infectious disease epidemiology, evaluates the evidence base for key interventions, and discusses barriers to implementation and strategies for improvement. Methods: A comprehensive review of peer-reviewed literature published between 2020 and 2025 was conducted using PubMed, Embase, Scopus, and WHO/CDC databases. Studies were selected based on relevance to water, sanitation, and hygiene (WASH) interventions, infection prevention and control (IPC), and environmental health. Results: Evidence consistently demonstrates that improving water quality, sanitation coverage, and hygiene practices significantly reduces the burden of waterborne, faecal-oral, and healthcare-associated infections. Key WASH interventions, including safely managed sanitation, handwashing with soap, and environmental surface disinfection, reduce diarrhoeal disease risk by up to 47%, respiratory infections by approximately 20%, and healthcare-associated infection (HAI) rates by over 60% when applied systematically. Major barriers include inadequate infrastructure, financial constraints, cultural norms, and weak governance of IPC programmes. Conclusion: Integrated, equity-focused WASH and IPC strategies aligned with Sustainable Development Goal 6 (SDG 6) targets are essential for breaking the cycle of infectious disease transmission. Strengthening environmental hygiene systems represents a highly cost-effective investment in global public health.
Patrick Chimuanya Etus1, Micheal Abimbola Oladosu2*, Moses Adondua Abah3, Okabeonye Sunday Agbo4, Bukola Oluwaseyi Olufosoye5, Comfort Oluwakemi Cambell6 (Mon,) studied this question.