Carbapenemase-producing Klebsiella pneumoniae bloodstream infections in neutropenic patients with haematological malignancies or aplastic anaemia: Analysis of 50 cases

Carbapenemase-producing Klebsiella pneumoniae (CP-Kp) are currently among the most important nosocomial pathogens in many geographic regions. A retrospective study was conducted between 2010 and 2014 in four hospitals located in a high-prevalence area (Athens, Greece) to describe the clinical features, treatment and outcomes of neutropenic patients with haematological diseases complicated with CP-Kp bloodstream infections. A total of 50 patients were identified, including 48 with haematological malignancies and 2 with aplastic anaemia. All patients had neutropenia (<500 cells/mm3), of whom 40 had <100 neutrophils/mm3. The probable source of bacteraemia was identified in 9 patients; in the remaining 41 patients the bacteraemia was considered primary. For definitive treatment, 30 patients received combination therapy (two or more active drugs), 10 received monotherapy (one active drug) and 4 received therapy with no active drug; the remaining 6 patients died within 48 h after the onset of bacteraemia. The 14-day all-cause mortality rate was 50%, 38% and 33% for those who received one, two or three active drugs respectively. In the Cox proportional hazards model, unresolved neutropenia [hazard ratio (HR) = 19.28, 95% confidence interval (CI) 2.31-160.69; P = 0.006], septic shock (HR = 3.04, 95% CI 1.06-8.78; P = 0.04) and treatment with one active drug (HR for monotherapy versus combination therapy = 3.95, 95% CI 1.23-12.65; P = 0.02) were independent predictors of death, whilst combination therapy was associated with lower mortality. These findings may assist physicians in making treatment decisions for neutropenic patients with CP-Kp infections.