Health care-associated infections (HAIs) affect patients and health systems every day, causing immense suffering, driving higher health-care costs and hampering efforts to achieve high-quality care for all. HAIs are often difficult to treat, are the major driver of antimicrobial resistance (AMR) and cause premature deaths and disability. The COVID-19 pandemic, as well as outbreaks of Ebola, Marburg and mpox are the most dramatic demonstrations of how pathogens can spread rapidly and be amplified in health care settings. But HAIs are a daily threat in every hospital and clinic, not only during epidemics and pandemics. Lack of water, sanitation and hygiene (WASH) in health care settings not only affects the application of infection prevention and control (IPC) best practices but also equity and dignity among both those providing and receiving care.