Epidemiology and clinical features of bloodstream infections in hematology wards: one year experience at the catholic blood and marrow transplantation center.

BACKGROUND

The aim of this study was to investigate the clinical features and epidemiology of bloodstream infections (BSIs) in 2 distinctive hematological wards of the Catholic Blood and Marrow Transplantation (BMT) center.

MATERIALS AND

METHODS

We retrospectively reviewed the medical data of patients who developed BSIs from June 2009 to May 2010 in 2 hematologic wards at the Catholic BMT center. Ward A is a 44-bed unit mainly conducting conventional high dose chemotherapy and ward B is a 23-bed unit exclusively conducting BMT.

RESULTS

Overall, 222 BSI episodes were developed from 159 patients. Acute myeloid leukemia in ward A and multiple myeloma in ward B were more frequent than in ward B and A, respectively. Sex, age, presence of neutropenia, shock, Pitt bacteremia score, type of central catheter, level of C-reactive protein, duration of admission days, type of BSI, overall mortality and distribution of organisms were not different between the 2 wards. There were 202 monomicrobial and 20 polymicrobial BSI episodes, including 2 fungemia episodes. The incidence rate of overall BSIs per 1,000 patient-days was higher in ward A than in ward B (incidence rate ratio 2.88, 95% confidence interval 1.97-4.22, P<0.001). Among 243 organisms isolated, the number of gram positives, gram negatives and fungi were 122, 119 and 2, respectively. Escherichia coli was the most common organism in both ward A and B (27.6% and 42.4%), followed by viridians streptococci (18.6% and 15.2%) and Klebsiella pneumoniae (13.3% and 9.0%). Extended spectrum beta-lactamase (ESBL) producers accounted for 31.9% (23/72) of E. coli and 71.0% (22/31) of K. pneumoniae. Out of 19 Enterococcus faecium, 7 isolates (36.8%) were resistant to vancomycin. The crude mortality rates at 7 and 30 days after each BSI episode were 4.5% (10/222) and 13.1% (29/222), and were significantly higher in the patients with shock compared with those without shock (20.5% vs. 1.1%, P<0.001 and 38.5% vs. 7.7%, P<0.001, respectively).

CONCLUSIONS

The incidence rate of BSIs was higher in patients receiving chemotherapy than those receiving BMT, but the distribution of organisms was not different between the 2 wards. E. coli was the most common causative BSI organism in hematologic wards followed by viridians streptococci and K. pneumoniae.