Incidence of Hospital-Acquired Pneumonia, Bacteraemia and Urinary Tract Infections in Patients with Haematological Malignancies, 2004–2010: A Surveillance-Based Study

OBJECTIVE: This study charted incidence trends of hospital-acquired (HA) pneumonia, bacteraemia and urinary tract infections (UTI) in a haematology department. METHODS: Prospective surveillance of hospital-acquired infections (HAI) was undertaken in a 42-bed haematology department of a university hospital. All patients hospitalized ≥48 hours between 1(st) January 2004 and 31(st) December 2010 were included. Definitions of HAI were based on a standardized protocol. The incidence was the number of events per 1000 patient-days at risk; only the first HAI was counted. Multivariate Poisson regression was fitted to assess temporal trends. RESULTS: Among 3 355 patients (58 063 patient-days at risk) included, 1 055 (31%) had HAI. The incidence of HA pneumonia, HA bacteraemia and HA UTI was respectively 3.3, 12.0 and 2.9 per 1000 patient-days at risk. HA bacteraemia incidence increased by 11% (95% confidence interval: +6%, +15%, P<0.001) per year, independently of neutropenia, central venous catheterization (CVC) and haematological disease. The incidences of HA pneumonia and HA UTI were stable. The most frequently isolated pathogens were Aspergillus spp. (59.2%) for pneumonia, coagulase-negative Staphylococcus (44.2%) for bacteraemia and enterobacteria (60%) for UTI. CONCLUSION: The incidence of bacteraemia increased, indicating that factors other than CVC exposure, including chemotherapy with its impact on the immune system, could explain this trend. Further analytic studies are needed to explore the factors that could explain this trend.