Nosocomial infection and antibiotic use: a second national prevalence study in Germany

In 2011, seventeen years after the first national study on the prevalence of nosocomial infections and antibiotic use in German hospitals, a second national prevalence study was carried out according to the specifications of the European Centre for Disease Prevention and Control (ECDC).

The ECDC protocol, containing uniform surveillance definitions and ascertainment methods, was implemented. The only infections counted were those that were active or under treatment with antibiotics on the day of the study. In addition to the representative sample required by the ECDC, which consisted of 46 hospitals, further hospitals participated on a voluntary basis.

Data on 41 539 patients in 132 hospitals were analyzed. The prevalence of infections that had arisen during the current hospital stay was 3.8% in the overall group and 3.4% in the representative sample of 9626 patients in 46 hospitals. The prevalence of all nosocomial infections, including those acquired before the current hospital stay and still present upon admission, was 5.1% in both the overall group and the representative sample. The prevalence of antibiotic use on the day of the study was 25.5% and 23.3% in the two groups, respectively.

The prevalence of nosocomial infection has not changed since 1994, but the prevalence of antibiotic use has increased. In interpreting these findings, one should bear in mind that confounders may have influenced them in different directions: The mean length of hospital stay is now shorter than in 1994, but the mean age of hospitalized patients is higher.