Immunosuppression and Intensive Care Unit-acquired Multidrug-resistant Bacteria

Antimicrobial resistance AMR is an emerging global threat to human health, and intensive care units (ICUs) are a 'hot spot' for the emergence and diffusion of multidrug-resistant (MDR) bacteria. ICU-acquired colonization and infection with MDR bacteria (ICU-MDR-col and ICU-MDR-inf, respectively) have been associated with higher ICU length-of-stay, duration of invasive mechanical ventilation and mortality. Immunocompromised patients account for an increasing proportion of ICU patients, and they are particularly prone to ICU-acquired infections, a significant proportion of which are caused by MDR pathogens. Recently, in a prospective multicenter study in France (CIMDREA, 8 ICUs, 750 patients), we found that immunocompromised patients had a lower cumulative incidence of ICU-MRD-col, but not ICU-MDR-inf (after adjustment for confounders). These results suggest that isolation measures and contact precautions could have a protective impact on cross-transmission of MDR bacteria in immunocompromised patients, even though our study fails to provide conclusive arguments for this. If confirmed, these findings could have an impact on antibiotic stewardship in immunocompromised critically-ill patients, a key element to control the spread of AMR in ICUs and beyond. Thus, we are planning to carry out the TANGERINE study, an observational prospective multicenter study in Europe, to confirm the findings of CIMDREA and provide a better understanding of the effect of isolation measures and contact precautions on the epidemiology of AMR in ICUs.