Prospective study of bacteraemia in cancer patients

Abstract

We performed a prospective assessment of the current epidemiology of bacteraemia in cancer patients hospitalized in 70 different adult and paediatric haematology and oncology departments. Over a 1-month period, microbiologists from 54 hospitals collected clinical data relating to patients with at least one positive blood culture. In addition, all strains isolated were assessed for their in vitro susceptibility to three broad-spectrum cephalosporins suitable for empirical treatment in cancer patients: cefpirome, cefepime and ceftazidime. A total of 494 different strains were isolated from 1,038 blood cultures taken from 403 different patients. Seventeen strains were isolated from 13 patients with various nonmalignant diseases, and these cases were excluded from analysis. Overall, 330 (69.2%) of the strains were isolated in patients with haematological malignancy and 147 (30.8%), in patients with solid tumours. There was no difference in the distribution of the species involved in bacteraemia between patients with haematological malignancy and patients with solid tumours: coagulase-negative staphylococci were the leading pathogens (50.6% and 44.9%, respectively), followed by E. coli (11.2% and 12.2% respectively), S. aureus (6.3% vs 7.5%), streptococci (4.8% vs 5.4%) and P. aeruginosa (5.2% vs 4.8%). All other species accounted for less than 5% in both groups. There was no difference in the strain distribution with age (≥ 15 years vs < 15 years) or type of underlying disease. S. aureus and Enterobacteriaceae bacteraemia were more frequent in patients with end-stage disease, while oral streptococci, Enterobacteriaceae and P. aeruginosa infections were more frequent in patients who were severely neutropenic. Digestive tract decontamination was associated with increased frequency of oral streptococci and decreased frequency of Enterobacteriaceae infections. All three cephalosporins demonstrated similar activity against E. coli, while cefpirome and cefepime appeared to be more effective against other Enterobacteriaceae. Ceftazidime had better activity against P. aeruginosa. Cefpirome was the most effective against Gram-positive cocci, especially oral streptococci and methicillin-susceptible staphylococci.