Why it works
Many respiratory and diarrhoeal infections spread by hands touching contaminated surfaces and then the face. Washing with soap physically removes and disrupts many pathogens.
When to wash
Key moments include before preparing or eating food, after using the toilet, after coughing or sneezing, after caring for someone unwell, and after touching animals or waste.
Where soap is scarce
Alcohol-based hand rub (at least 60% alcohol) is a recognized alternative when hands are not visibly dirty. Public health agencies publish locally adapted guidance.