Is surveillance of Pseudomonas aeruginosa carriage in intensive care units useful?

To evaluate the potential interest of screening of Pseudomonas aeruginosa on admission and during hospitalisation in intensive care units patients. A retrospective study was carried out in two adult ICU of the University-Hospital of Besançon in 2007. P. aeruginosa screening was performed on admission and once a week during ICU stay. Clinical samples positive with P. aeruginosa were collected. Among the 754 patients included, 146 had a screening sample positive giving an average incidence of 19.4 per 100 patients. Thirty-five were imported and 111 ICU-acquired. Sixty-one patients had at least one positive clinical sample, that is an incidence 8.1 cases per 100 admitted patients. Sensibility, specificity, positive and negative predictive values of screening as an indicator of subsequent infection were 54.1%, 86.9%, 26.6% and 95.6%, respectively. Screening samples are necessary to assess P. aeruginosa endemicity in intensive care units. The high negative predictive value of screening suggests that use of specifics anti-Pseudomonas antimicrobials could be reduced. However, the benefit of this strategy remains to be evaluated.