What is the evidence for a causal link between hygiene and infections?
This is a review of the evidence from 54 studies published during 1980-2001 that measured the impact of hygiene measures on infection rates. The authors concluded that implementation or changes in personal and environmental hygiene has a positive role in reducing risk of infection, which was generally greater than 20% for most interventions). Lancet Infectious Diseases 2002;2:103-110.