Although promotion of safe hygiene is the single most cost-eff ective means of preventing infectious disease,
investment in hygiene is low both in the health and in the water and sanitation sectors. Evidence shows the benefi t
of improved hygiene, especially for improved handwashing and safe stool disposal. A growing understanding of
what drives hygiene behaviour and creative partnerships are providing fresh approaches to change behaviour.
However, some important gaps in our knowledge exist. For example, almost no trials of the eff ectiveness of
interventions to improve food hygiene in developing countries are available. We also need to fi gure out how best to
make safe hygiene practices matters of daily routine that are sustained by social norms on a mass scale. Full and
active involvement of the health sector in getting safe hygiene to all homes, schools, and institutions will bring
major gains to public health.