The acquisition of Multi-drug resistant bacteria in patients admitted to COVID-19 intensive care units: a monocentric retrospective case control study

Background: Whether the risk of multidrug resistant bacteria (MDRB) acquisition in the intensive care unit (ICU) is increased during the COVID-19 crisis is unknown. Our aim was to measure the rate of MDRB acquisition in patients admitted in COVID-19 ICU and to compare it with pre-COVID-19 controls.Methods: This single center case control study included adult patients admitted to COVID-19 ICUs for more than 48h. Patients were screen twice a week for MDRB carriage during ICU stay. We compared the rate of MDRB acquisition of COVID-19 patients with a cohort of patients admitted for subarachnoid hemorrhage (SAH) and matched on length of ICU stay using a competing risk analysis.Results: Among 72 patients admitted to the COVID-19 ICUs, 24 (33%) patients acquired 31 MDRB during ICU stay. The rate of MDRB acquisition was 30/1000 patient-days. Patients that acquired MDRB had received more antimicrobial therapy [22 (92%) vs 34 (78%, p=0.05] and had a longer exposure time [12 days (8-18) vs 5 days (2-18), p=0.02]. The rate of MDRB acquisition in matched SAH patients was 18/1000 patient-days. When compared to SAH retrospective cohort, being admitted to a COVID-19 ICU was associated with a numerically higher proportion of MDRB acquisition. This association did not reach statistical significance in the multivariable competing risk analysis (sHR 1.71 (CI 95% 0.93-3.21).Conclusion: Acquisition of MDRB was frequent during the COVID-19 first wave in ICU patients. Despite physical isolation, it was similar to patients admitted to the same ICU in previous years.