Pseudomonas Aeruginosa Infections in Cancer Patients

Abstract

Cancer patients, particularly those with neutropenia, are at increased risk of developing bacterial infections (1). In the four decades since the association between neutropenia and infection was recognized, the epidemiology of bacterial infection in cancer patients has undergone several changes, with gram-positive organisms and gram-negative bacilli being the predominant pathogens at different stages. Many of these epidemiologic shifts have been influenced by changes in the nature and intensity of chemotherapeutic and immunosuppressive regimens, prophylactic and empiric antimicrobial regimens, and the increased usage of vascular access catheters and prosthetic devices (2,3).Pseudomonas aeruginosa emerged as a common cause of gram-negative infection in cancer patients during the 1960’s and, before the availability of agents such as carbenicillin, was associated with mortality rates in excess of 90% (4). Since then, the availability of potent anti-pseudomonal agents and significant improvements in supportive care have reduced the mortality to approximately 25–30% (5,6). Substantial regional and institutional variations in the frequency of infections caused by P. aeruginosa have been documented (7,8). The treatment of P. aeruginosa infections continues to foster much discussion and debate among various experts, some of whom advocate the use of synergistic, bactericidal combinations for the treatment of all pseudomonal infection in neutropenic patients, whereas others do not. These issues will be discussed in this chapter, with an emphasis on current trends in North America.