[Current challenges on hospital hygiene].

Although microorganisms are the main cause of nosocomial infections, they are by no means their only determinants. Patient-associated factors play a major role (especially immune status), the therapeutic conditions (personnel behaviour, 'devices') and the patient's environment. The hospital infection control team is responsible for implementing and operating an efficient and cost-effective infection control and prevention system. Scientific data must be evaluated and every effort made to continuously improve recommendations. In order to implement an efficient and cost-effective infection control and prevention system, the infection control team must formulate sound, evidence-based recommendations and question established 'rituals'. Inappropriate measures, e. g. the routine disinfection of floors in wards and hallways place a burden on staff, patients and the environment, and distract staff from other critical measures such as proper hand hygiene. Nosocomial pneumonia, urinary tract infections, surgical wound infections and catheter-associated sepsis are the commonest hospital-acquired infections, and Intensive Care Units have become the foci of antibiotic resistance. Although the antimicrobial resistance situation is better in Germany than in other countries, e. g. Eastern and Southern European countries and the USA, substantial regional differences exist. The increase in methicillin (oxacillin) resistant S. aureus (MRSA) is particularly worrying. Building up an effective surveillance system for nosocomial infections, as demanded by the new German infection control act has far-reaching implications and entails recording risk-adjusted infection rates (KISS project = Hospital Infection Surveillance System of the National Reference Center for Hospital Hygiene in cooperation with the Robert Koch-institute). Proper collaboration between hospital staff in implementing infection control measures, and especially hand hygiene is of paramount importance.