The impact of the COVID-19 pandemic on nosocomial infections and antimicrobial resistance (AMR) in intensive care units

The COVID-19 pandemic may have influenced healthcare-associated infections (HAIs) and antimicrobial resistance (AMR), particularly in intensive care units (ICUs). We performed a retrospective study in the ICU of Ibn Tofail Hospital, Marrakech, Morocco from March to September 2022. Patients hospitalized for more than 48 h were included. HAIs were defined according to CDC criteria, and antimicrobial susceptibility testing followed EUCAST guidelines. Results were compared with pre-pandemic data from 2019. Of 187 admitted patients, 145 were eligible, and 38 developed an HAI (26.3 %). The most frequent infections were pneumonia (37 %), catheter-related infections (27.5 %), and urinary tract infections (16.1 %). Among 112 isolates, Gram-negative bacteria predominated (82.7 %), mainly <i>Klebsiella pneumoniae</i> (26.8 %), <i>Acinetobacter baumannii</i> (17.9 %), and <i>Pseudomonas aeruginosa</i> (14.3 %). Compared with 2019 (98 isolates), <i>K. pneumoniae</i> increased significantly (17.3 % vs. 26.8 %, p = 0.048). Resistance to ceftazidime rose in <i>P. aeruginosa</i> (22.2 % vs. 56.3 %, p = 0.042), while methicillin resistance in <i>Staphylococcus aureus</i> declined (75.0 % vs. 25.0 %, p = 0.044). No significant changes were observed in carbapenem resistance. Multidrug resistance remained widespread (45.9 % vs. 50.9 %, p = 0.458). HAIs in this ICU were mainly due to Gram-negative bacteria, with notable shifts in <i>K. pneumoniae</i> prevalence and specific resistance patterns after the pandemic. While multidrug resistance remains a pressing concern, most changes were limited in scope. These findings provide locally relevant data that can inform infection control and AMR surveillance strategies in North African ICUs.