Changes in the microbiological epidemiology of febrile neutropenia in autologous stem cell transplant recipients

Background: The aim of the study was to explore the incidence, microbiological etiology and outcome of febrile neutropenia among adult hematological patients following autologous stem cell transplantation (ASCT). Methods: The study population consisted of patients who received ASCT between 1 December 2006 and 30 November 2012. The epidemiology was compared to a retrospective series covering eleven previous years at the same institution. Non-Hodgkin lymphoma (NHL) patients, who had been identified as a risk group in the retrospective study, received ciprofloxacin prophylaxis from January 2008. Results: Altogether, 142 out of 178 of the included patients (80%) developed febrile neutropenia. The blood cultures were positive in 24 cases (17%). Of all bacteremia's, 88% were caused by Gram-positive and 12% by Gram-negative bacteria. The number of Gram-negative bacteremia were significantly lower in the prospective study compared to the retrospective study (3/142, 2.1% vs. 23/265, 8.7%, p = .01). Pseudomonas aeruginosa was prevalent in the retrospective series but not discovered in the present series. Enterococcus faecium was found more frequently in the prospective study (6/142, 4.2 vs. 2/265, 0.8%, p = .02). The infectious mortality among patients with febrile neutropenia was 4/142 (2.8%) in the present series and 9/265 (3.4%) in those who received ASCT in 1996-2006. Conclusion: Most patients who received ASCT developed febrile neutropenia and a minority had bacteraemia. In comparison to the earlier time period, the incidence of Gram-negative bacteraemias decreased, probably due to ciprofloxacin prophylaxis in NHL patients, but simultaneously the incidence of Enterococcus bacteraemias increased. Infectious mortality during febrile neutropenia was low in both series.