Risk factors for healthcare-associated infection caused by carbapenem-resistant Pseudomonas aeruginosa.

BACKGROUND/PURPOSE: The incidence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) related healthcare-associated infection (HAI) has increased in recent year worldwide. This study is to investigate the risk factors associated with CRPA infections in a university hospital setting in Taiwan to provide more information for clinician and infection control system.

METHODS: A retrospective cross-sectional study was conducted from January 1st, 2009 to June 30th, 2014. Patients with P. aeruginosa related HAI were included and divided into the CRPA case group and carbapenem-susceptible Pseudomonas aeruginosa (CSPA) control group. The medical records were reviewed to identify risk factors for CRPA HAI and mortality. Patients with prior use of any anti-pseudomonal carbapenems were included in subgroup analysis.

RESULTS: 395 cases of P. aeruginosa infection were enrolled from total of 3263 HAI events; 63 were CRPA and 332 were CSPA. The prevalence of CRPA was 15.9% (63/395). Significant risk factors related to CRPA infection were longer time at risk, prior use of anti-pseudomonal carbapenems, and prior use of aminoglycoside (p < 0.05, 0.01, and 0.05). Furthermore, anti-pseudomonal carbapenem monotherapy did not significantly increase risk for CRPA infection.

CONCLUSION: The worldwide CRPA prevalence has been on the raise and Taiwan has been also keeping up with the trend. Antimicrobials usage should be monitored carefully, especially with carbapenems and aminoglycoside. Clinicians should be award of and understand about the risk of CRPA infection, which increases by 1% with each hospitalization day.