Epidemiology of bloodstream infections in patients with haematological malignancies with and without neutropenia.

All bacterial isolates from 7058 patients admitted to haemato-oncology wards at National Taiwan University Hospital between 2002 and 2006 were characterized. In total 1307 non-duplicate bloodstream isolates were made from all patients with haematological malignancy; 853 (65%) of these were from neutropenic patients. Gram-negative bacteria predominated (60%) in neutropenic isolates with Escherichia coli (12%), Klebsiella pneumoniae (10%), Acinetobacter calcoaceticus-baumannii complex (6%), and Stenotrophomonas maltophilia (6%) the most frequent. Coagulase-negative staphylococci (19%) and Staphylococcus aureus (4%) were the most common Gram-positive pathogens. Resistance to ciprofloxacin was found in 50% of E. coli and 20% of K. pneumoniae isolates from neutropenic patients. Extensively drug-resistant A. calcoaceticus-baumannii complex and vancomycin-resistant enterococci were also found during the study period. Emerging antimicrobial resistant pathogens are an increasing threat to neutropenic cancer patients.