Assessing the impact of antimicrobial exposure and infection control measures on the spread of vancomycin-resistant enterococci (AEGON)
Recent studies show that there has been an increasing spread of vancomycin-resistant enterococci (VRE) in hospital patients in Germany in recent years. Enterococci are abundant in the intestines of humans (and animals) and are generally only slightly pathogenic. However, infections caused by these resistant pathogens pose an immediate threat to immunocompromised patients: In the presence of an infection, the available treatment options are reduced, which can lead to poorer treatment results and a longer duration of the disease. The AEGON project is investigating intensified infection control and antibiotic stewardship measures to reduce the incidence of VRE infections.
Data from previous studies of the DZIF (for example from the "R-NET" project) indicate a rapid spread of vancomycin-resistant enterococci, especially Enterococcus faecium (VREf) in German hospitals.
Healthy individuals come into contact with VREf mainly via the food chain, contaminated drinking water or animal contact. If intestinal colonization with these pathogens occurs, the simultaneous administration of antibiotics leads to increased selection pressure: while sensitive bacteria are killed, resistant bacteria can multiply unhindered under antibiotic treatment. The pathogen density can then increase to such an extent that the microbiome becomes dominated. This very high pathogen load is associated with an increased risk of bloodstream infections in immunocompromised patients. The infection of other patients is also more likely.
It is assumed that infection control (IC) and antimicrobial stewardship (AMS) measures are effective interventions to interrupt the sequence of colonization, domination and subsequent infection.
IC measures focus particularly on improving cleaning and disinfection of patient rooms, improved hand hygiene and contact isolation of patients. AMS interventions focus on the sustainable promotion of a rational use of antibiotics to reduce the selection pressure.
Inadequate understanding of the mode of action as well as a lack of prioritization possibilities of the individual IC and AMS measures lead to different recommendations and continued outbreak events, which put patients at risk of infection with vancomycin-resistant Enterococcus faecium pathogens. A deeper understanding of the epidemiology of these outbreaks is therefore an absolute prerequisite for the successful development and implementation of prevention measures.
The purpose of this study is to provide a detailed analysis of the factors involved in the dissemination of VREf. In addition, antibiotic therapies will be evaluated with respect to prescription quality and the influence on colonization and domination of these bacterial populations. The study therefore consists of two parts, which will be conducted at all participating study sites and include two different patient cohorts:
- Part 1 will focus on the collection and analysis of rectal swabs from newly enrolled VREf negative patients at high risk of nosocomial VREf acquisition and the evaluation of past antibiotic therapy.
- In part 2, environmental studies will be performed in newly enrolled single rooms of patients who are already VREf positive. In addition, data on the antibiotic exposure of these patients will be documented in order to identify links between antibiotic administration and VREf contamination burden.
