Pseudomonas aeruginosa bloodstream infections in children and adolescents: risk factors associated with carbapenem resistance and mortality

Abstract

Pseudomonas aeruginosa bloodstream infections (PA-BSIs) are a serious disease and a therapeutic challenge due to increasing resistance to carbapenems. Our objectives were to describe the prevalence and risk factors associated with carbapenem resistance (CR) and mortality in children with PA-BSI. A retrospective, multi-centre study was carried out, including patients aged <20 years with PA-BSI in four tertiary hospitals in Madrid (Spain) during 2010-2020. Risk factors for CR PA-BSIs and 30-day mortality were evaluated in a multi-variable logistic regression model. In total, 151 patients with PA-BSI were included, with a median age of 29 months (interquartile range: 3.5-87.1). Forty-five (29.8%) cases were CR, 9.9% multi-drug resistant and 6.6% extensively drug resistant. The prevalence of CR remained stable throughout the study period, with 26.7% (12/45) of CR mediated by VIM-type carbapenemase. Patients with BSIs produced by CR-PA were more likely to receive inappropriate empiric treatment (53.3% vs 5.7%, P<0.001) and to have been previously colonized by CR-PA (8.9% vs 0%, P=0.002) than BSIs caused by carbapenem-susceptible P.aeruginosa. CR was associated with carbapenem treatment in the previous month (adjusted odds ratio (aOR) 11.15) and solid organ transplantation (aOR 7.64). The 30-day mortality was 23.2%, which was associated with mechanical ventilation (aOR 4.24), sepsis (aOR 5.72), inappropriate empiric antibiotic therapy (aOR 5.86), and source control as a protective factor (aOR 0.16). This study shows a concerning prevalence of CR in children with PA-BSIs, leading to high mortality. Inappropriate empiric treatment and sepsis were associated with mortality. The high prevalence of CR with an increased risk of inappropriate empiric treatment should be closely monitored.