From 'one size fits all' to personalized infection prevention.

One hundred years ago, many healthcare- associated infections (HAIs) had an exogenous origin, which means they were caused by micro-organisms from other patients, healthcare workers or the hospital environment. A smaller proportion was due to endogenous micro-organisms from the patients' own microbial flora. Meanwhile, many improvements have been achieved. The majority of devices used for diagnosing and treating the patients are now single- use items. The disinfection and sterilization measures used for reprocessing the remaining devices are on a very high safety level (at least in high-income countries) and cross- transmission via instruments is a very rare seldom event. Hand hygiene has also improved substantially. We have observed an increase in hand rub consumption of more than 100% during the last 12 years in Germany. For these measures the 'one size fits all approach' is appropriate because they have to be applied for all patients independent of their diseases and pathogens. Today, we see a small percentage of exogenous HAIs. The majority of HAI have an endogenous origin. Of course, it is still necessary to focus on basic or standard infection-control measures to prevent transmission of micro-organisms. However, the majority of HAIs have an endogenous origin now. Thus our measures should not only focus on preventing transmission of microorganisms, but also on prevention of infections. Therefore, a personalized infection prevention approach is now appropriate and examples will be presented.