Trends in nosocomial bacteraemias: results from a university hospital in the Netherlands

Abstract number: 1733_449

Ammerlaan H.S.M., Troelstra A., Blok H., Bonten M.J.M.

Objective: To evaluate the burden (morbidity and mortality) of nosocomial bacteraemias (NB) in a MRSA-free hospital.

Methods: The UMC Utrecht is a 997-bed tertiary care centre with about 21,100 admissions annually. We analyzed all patients admitted between January 1996 and December 2005, aged ≥18. Day-care admissions and those treated in psychiatry were excluded. The hospitals' microbiological database was linked to the patient-administrative system, thereby providing all blood culture results and data on gender, date of birth, department, length of stay, and mortality at hospital discharge. NB was defined as isolation of bacteria or yeast from ≥1 blood culture set >2 days after hospital admission, with only the first episode analyzed. Skin organisms commonly associated with contamination, were excluded. Annual incidence and mortality rates of NB were calculated, with subgroup analysis for different micro-organisms.

Results: 1,769 episodes of NB were identified, with incidence rates increasing from 89.9 per 100,000 patient-days in 1996 to 112.6 in 2005, due to an increase in both Gram-positive and Gram-negative infections. The RR of male on acquiring NB was 1.6 compared to female. The RR of patients in the ICU was 6.0 compared to the other departments. In this period no trend towards increasing resistance was found, accept for a striking increase of amoxicillin resistance among Enterococcus species in the 2nd half of the study from 12.1% to 46.6% (p = 0.001). The length of stay (LOS) within the hospital decreased from 10.7 (95% CI: 10.6–10.8) in 1995 to 7.9 (95% CI: 7.8–7.9) days in 2005. The average LOS for patients with NB did not change between 1995 and 2004 (50.4 days (95% CI: 48.0–52.7)), but decreased in 2005 to 41.5 days (95% CI: 36.2–46.8). Average LOS for patients with NB ranged from 39.6 days (95% CI: 24.6–54.5) for Morganella morganii to 73.7 days (95% CI: 49.2–98.1) for Serratia species. Overall hospital mortality for patients with NB was 26.4% (ranging from 12.0% for Acinetobacter species to 52.1% for Candida). The RR to die in the hospital for patients with NB was 8.5 when compared to non-affected patients. This did not change significantly from 1996 to 2005.

Conclusion: The burden of nosocomial bacteraemias did not change significantly over the past 10 years within the UMC Utrecht. While the mean LOS within the hospital decreases, the incidence rate of HAB increases, suggesting an increasing severity of illness of hospitalised patients.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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