Outbreaks of nosocomial infections: lessons learned and perspectives

The review summarizes the results of selected outbreak reports and systematic analyses of nosocomial outbreaks from 2007 and focuses on different aspects of hospital epidemiology and infection control.

A single outbreak report is likely be influenced by the local setting. In contrast, a systematic analysis of a large number of similar outbreaks draws a much better picture of the real conditions on the pathogen's reservoirs, on modes of transmission, and on appropriate infection control measures to prevent the spread of the microorganism. Isolation, unit closures, sick leave, cleaning, and diagnostic/therapeutic measures may lead to enormous costs during an outbreak. Thus, cost calculations of outbreaks should be performed to justify future expenses for infection control. Mathematic modeling is a fairly new approach to estimate the risk of pathogen transmission in outbreak settings. Examples are shown to differentiate between epidemic and sporadic infections and to evaluate the influence of infection control interventions.

Outbreak reports may add some very important information to the understanding of transmission and infection control. There is a need for a more structured publication of nosocomial outbreaks to ensure that no key data are lacking in the article.