Multidrug-Resistant Bacterial Colonization and Infections in Large Retrospective Cohort of Mechanically Ventilated COVID-19 Patients1

Few data are available on incidence of multidrug-resistant organism (MDRO) colonization and infections in mechani-cally ventilated patients, particularly during the COVID-19 pandemic. We retrospectively evaluated all patients ad-mitted to the COVID-19 intensive care unit (ICU) of Hub Hospital in Milan, Italy, during October 2020-May 2021. Microbiologic surveillance was standardized with active screening at admission and weekly during ICU stay. Of 435 patients, 88 (20.2%) had MDROs isolated & LE;48 h af-ter admission. Of the remaining patients, MDRO coloni-zation was diagnosed in 173 (51.2%), MDRO infections in 95 (28.1%), and non-MDRO infections in 212 (62.7%). Non-MDRO infections occurred earlier than MDRO infec-tions (6 days vs. 10 days; p<0.001). Previous exposure to antimicrobial drugs within the ICU was higher in MDRO patients than in non-MDRO patients (116/197 [58.9%] vs. 18/140 [12.9%]; p<0.001). Our findings might serve as warnings for future respiratory viral pandemics and call for increased measures of antimicrobial stewardship and infection control.