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

Abstract

Few data are available on incidence of multidrug-resistant organism (MDRO) colonization and infections in mechanically ventilated patients, particularly during the COVID-19 pandemic. We retrospectively evaluated all patients admitted 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 ≤48 h after admission. Of the remaining patients, MDRO colonization 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 infections (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.

Understanding the burden of antibiotic resistance: a decade of carbapenem-resistant Gram-negative bacterial infections in Italian intensive care units

“…Similarly, we observed a steadily decreasing trend of prevalence of CR-GNB infections from 2015 to 2018, followed by a new increase in 2020. The unprecedented threat posed to ICU during the SARS-CoV-2 pandemic indeed provided an ideal landscape for the development of infectious complications and spread of MDR strains ( Grasselli et al, 2021 ; Mangioni et al, 2023a ) and may serve as a crucial example for the management of future viral pandemics. The large numbers of patients requiring enhanced care, combined with the need for ICU beds and the creation of new emergency facilities, severely limited infection control practices, favoring outbreaks and the spread of nosocomial pathogens.…”

Incidence, microbiological and immunological characteristics of ventilator-associated pneumonia assessed by bronchoalveolar lavage and endotracheal aspirate in a prospective cohort of COVID-19 patients: CoV-AP study

“…However, we found MDROs in less than 3% of VAP with conventional culture and 7.3% with molecular microbiology, much lower than what was reported in previous studies by Grasselli et al in Italy and Moreno et al in France at 35% and 28% respectively [ 18 , 28 ]. Implementing antimicrobial stewardship (AMS) and preventive strategies both prior to and during the ICU stay has likely contributed to sharply reduce the burden of MDROs across different pandemic waves [ 14 , 29 ].…”

“…On the other, they directly impacted major clinical, laboratory and radiologic parameters employed in VAP diagnosis [ 12 ]. VAP has been reported in up to 79% of mechanically ventilated COVID-19 patients [ 13 ], with a high incidence of MDROs [ 14 ]. Accurate recognition of microbiologically confirmed VAP is of utmost importance in this setting.…”