Händehygiene und nosokomiale Infektionen: Die Evidenzbasis

Hand hygiene is the single most effective intervention for preventing healthcare-associated infections (HAIs). The evidence spans nearly two centuries:

1. Semmelweis (1847) – Chlorinated lime handwashing reduced puerperal fever mortality from ~18% to <2% in the Vienna General Hospital maternity clinic.
2. Observational studies – Consistently demonstrate inverse correlation between healthcare worker hand hygiene compliance and HAI rates (C. difficile, MRSA, VRE, Gram-negative bacteremia).
3. Randomized controlled trials – Multimodal hand hygiene campaigns (alcohol-based hand rub, education, feedback, reminders, leadership engagement) reduce HAI incidence by 30–50%.
4. WHO “5 Moments” framework – Before patient contact, before aseptic task, after body fluid exposure, after patient contact, after patient surroundings contact. Global standard since 2009.

Mechanism: Alcohol-based hand rubs (60–80% ethanol/isopropanol) rapidly inactivate enveloped viruses, most bacteria, and fungi by protein denaturation. Soap and water mechanically remove spores (C. difficile, Bacillus) and visible soil.

Sustained compliance >80% is the benchmark for HAI reduction. It requires system-level commitment—not just individual effort.