Treatment of Penicillin-Resistant Pneumococcal Bacteremia in Neutropenic Patients with Cancer

Abstract

We identified 17 cases of pneumococcal bacteremia among 340 neutropenic cancer patients with bacteremia. Pneumonia was more frequent in patients with pneumococcal bacteremia than in those with bacteremia due to other organisms: 12 (71%) of 17 patients with pneumococcal bacteremia had pneumonia, whereas only 23 (7%) of 323 patients with nonpneumococcal bacteremia had pneumonia (P < .001). Eight (47%) of the 17 episodes of pneumococcal bacteremia were caused by penicillin-resistant strains (MICs ranged from 0.12 μg/mL to 4 μg/mL); these penicillin-resistant pneumococci showed varying degrees of diminished susceptibility to all 13-lactams studied, especially ceftazidime (MICs of this drug ranged from 1 μg/mL to 64 μg/mL). Imipenem was the β-lactam agent most active against these organisms (MICs ranged from 0.03 μg/mL to 0.25 μg/mL). Patients with penicillin-resistant pneumococcal bacteremia received inappropriate empirical antibiotic therapy more often than did patients with bacteremia due to susceptible strains (i.e., 4 (50%) of 8 patients vs. 0 of 9, respectively; P < .05). Eight (47%) of the 17 patients with pneumococcal bacteremia died. In areas where penicillin-resistant pneumococci are highly endemic, these findings should be considered in selecting empirical antibiotic therapy for neutropenic patients with cancer who are suspected of having pneumonia.