Development of a surveillance system for nosocomial infections: the component for neonatal intensive care units in Germany
Introduction
Nosocomial infections in newborns have been associated with prolonged morbidity, significantly higher mortality and significantly greater hospital costs. Along with various other methods for prevention, the surveillance of nosocomial infections has been shown to be valuable for reducing infection rates, particularly when the data produced can be compared with reference data.1 The establishment of a national surveillance system is therefore useful. The American National Nosocomial Infections Surveillance (NNIS) system of the Centers for Disease Control and Prevention (CDC) had already created a component for neonatal nosocomial infections. One hundred and forty-six neonatal intensive care units (NICUs) are currently participating, with more than 4.3 million patient days having already been registered.2., 3. Enormous experience has been gained. However, only very limited experience was available in the field in Germany 10 years ago.4., 5.
For this reason we recommended that colleagues from the NICUs of our university hospital should use the methods and definitions of the American NNIS system for surveillance of nosocomial infections as a basis for establishing surveillance in the NICUs. However, we felt that the CDC definitions for children under one year need some modifications for neonates. This was the first step towards the development of our own surveillance component for nosocomial infections in NICUs, a development that continued over a period of seven years.
The present article describes the various steps in the development of a surveillance component for nosocomial infections in NICUs within the German nosocomial infection surveillance system KISS (Krankenhaus-Infektions-Surveillance-System), which currently includes 66 NICUs with an overview of more than 130 000 patient days. The reasons for modification of the original NNIS methods and the advantages and disadvantages of some of the modifications will be discussed.
Section snippets
First step: developing modified definitions for nosocomial infections and their evaluation
The CDC definitions for pneumonia und primary bloodstream infections (BSI) were developed for all patients of less than one year of age.6 Because of the special physiological situation in neonates compared with older children, the neonatologists in our university hospital did not fully accept CDC definitions. For example, fever does not occur in neonates, because the nurses immediately regulate the incubator temperature, and signs such as coughing and wheezing in the diagnosis of pneumonia are
First step
During this period 677 neonates were admitted and stayed for at least 24 h in the unit, 55 (8%) having a birthweight of less than 1500 g. These newborns, however, developed 61% of all the nosocomial infections recorded. The most frequent nosocomial infections were primary bloodstream infections (BSI) (41.1%), followed by NEC 25.6%), skin infections (11.1%) and pneumonia (7.8%). There was a high level of agreement between the criteria for the central line-associated primary BSI rate (κ=0.92) and
Discussion
By describing the process of developing a surveillance component for NICUs in Germany, we wish to demonstrate the long route necessary for the development of a surveillance system in a patient group with specific nosocomial infection risk factors, which is suitable for Germany and accepted by clinicians. Such a process requires a motivated group of infection control personnel with experienced hospital epidemiologists and dedicated clinicians in charge over a long time period. It is, of course,
Acknowledgements
This project has been supported by the German Ministry of Health since 2001. The authors thank the colleagues from the hospitals participating and, in particular, the infection control nurses of the Berlin neonatology departments for their substantial contribution to the development of the surveillance system.
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