Multidrug-resistant Pseudomonas aeruginosa bloodstream infections

risk factors and mortality

TUMBARELLO, M.
REPETTO, E.
TRECARICHI, E. M.
BERNARDINI, C.
DE PASCALE, G.
PARISINI, A.
ROSSI, M.
MOLINARI, M. P.
SPANU, T.
VISCOLI, C.
CAUDA, R.
BASSETTI, M.

¹ Institute of Infectious Diseases, Catholic University of the Sacred Heart, Roma, Italy
² Infectious Diseases Division, S. Martino Hospital and University of Genoa School of Medicine, Genoa, Italy
³ Laboratory Unit, S. Martino Hospital, Genoa, Italy
⁴ Institute of Microbiology, Catholic University of the Sacred Heart, Roma, Italy

^* Author for correspondence: Dr M. Tumbarello, Istituto Malattie Infettive, Università Cattolica del Sacro Cuore, Largo A. Gemelli 8, 00168 Roma, Italy. (Email: [email protected])

(Accepted 3 December 2010; first published online 13 January 2011)

Epidemiology & Infection 139(11):p 1740-1749, November 2011.

SUMMARY

We retrospectively studied patients diagnosed with P. aeruginosa bloodstream infections (BSIs) in two Italian university hospitals. Risk factors for the isolation of multidrug-resistant (MDR) or non-MDR P. aeruginosa in blood cultures were identified by a case-case-control study, and a cohort study evaluated the clinical outcomes of such infections. We identified 106 patients with P. aeruginosa BSI over the 2-year study period; 40 cases with MDR P. aeruginosa and 66 cases with non-MDR P. aeruginosa were compared to 212 controls. Independent risk factors for the isolation of MDR P. aeruginosa were: presence of central venous catheter (CVC), previous antibiotic therapy, and corticosteroid therapy. Independent risk factors for non-MDR P. aeruginosa were: previous BSI, neutrophil count <500/mm³, urinary catheterization, and presence of CVC. The 21-day mortality rate of all patients was 33·9 %. The variables independently associated with 21-day mortality were presentation with septic shock, infection due to MDR P. aeruginosa, and inadequate initial antimicrobial therapy.