Risk factors for Pseudomonas aeruginosa VIM colonization or infection in the ICU: Case-control study

Abstract

Carbapenem-resistant strains of Pseudomonas aeruginosa (CRPA) have become a major health care concern in many countries, against which anti-infective strategies are limited and which require adequate infection control interventions. Knowing the different modes of transmission of CRPA in intensive care units (ICUs) would be helpful to adapt the means of prevention. The aim of this retrospective case-control study was conducted between January 1, 2017 and February 28, 2022 to identify the risk factors for the acquisition of CRPA in ICUs. During the study period, 147 patients were included (49 cases and 98 controls). Among the 49 patients, 31 (63%) acquired CRPA in clusters and 18 (37%) sporadically. Aunivariate analysis showed that 4 variables were associated with CRPA acquisition, including (1) prior antibiotic prescriptions, (2) admission to rooms 203 and 207, (3) severity of illness at admission, and (4) use of mechanical ventilation. Multivariate analysis identified 3 factors of CRPA acquisition, including admission to room 203 (odds ratio [OR]=29.5 [3.52-247.09]), previous antibiotic therapy (OR=3.44 [1.02-11.76]), and severity of condition at admission (OR=1.02 [1-1.04]). Our study suggests the role of a contaminated environment in the acquisition of CRPA in the ICU, along with antibiotic use.