Clin Infect Dis

BACKGROUND: Issue of contact precautions as contributory factors for reducing P. aeruginosa (Pa) infections in intensive care units (ICUs) remains questioned. We evaluated the impact of the addition of contact precautions to standard precautions for Pa-positive patients on the incidence of ICU-acquired Pa infections. METHODS: In this multicenter cluster-randomized crossover trial, 10 French ICUs were randomly assigned (1:1) to sequence 0-1 (6-month control period [CP]/3-month washout period/6-month intervention period [IP]) or sequence 1-0 (6-month IP/3-month washout period/6-month CP). A surveillance screening program for Pa was implemented. Competing-risks regression models were built with death and discharge without the occurrence of ICU-acquired Pa infection (the primary outcome), as competing events. Models were adjusted for within-ICU correlation, patient- and ICU-level covariates. The Simpson diversity index (SDI) and the transmission index (TI) of Pa isolates were derived from pulsed-field gel electrophoresis typing. RESULTS: Within recruited ICUs, the cumulative incidence and the incidence rate of ICU-acquired Pa infections were 3.38% (55/1625) vs 3.44% (57/1658) and 3.31 vs 3.52 per 1 000 patient-days at risk during CP and IP, respectively. Multivariable models indicated that the intervention did not significantly change the cumulative incidence (subdistribution hazard ratio 0.91, 95% confidence interval [CI] 0.49-1.67, p=0.76) and the rate (cause-specific hazard ratio 1.36, 95%CI 0.71-2.63, p=0.36) of the primary outcome. SDI and TI did not significantly differ between CP and IP. CONCLUSIONS: The addition of contact precautions to standard precautions for Pa-positive patients with a surveillance screening program does not significantly reduce ICU-acquired Pa infections in non-outbreak situations