Epidemiologic surveillance of nosocomial infections in the intensive care unit: role of risk factors, emerging pathogens and cross-transmission

Abstract number: 1732_203

Agodi A., Barchitta M., Cipresso R., Giaquinta L., Romeo M., Denaro C.

Objectives: Nosocomial infections surveillance was performed in an Italian ICU in order to pretest the HELICS protocol before its nationwide implementation, and to evaluate the impact and the routes of acquisition of three emerging multiresistant pathogens, Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia by determining: (i) the occurrence of carriage on admission; (ii) the microrganism-specific ICU-acquired infection rates, by site; (iii) the impact of cross-transmission using molecular typing data, and (iv) the individual risk factors for infection.

Methods: A six-months surveillance survey was performed at the ICU of an Italian Hospital, in accordance with the HELICS protocol, excluding patients staying less than three days. An electronic data form, was designed using the SPSS Data Entry Enterprise Server (SPSS Inc.). Clonality was determined by macrorestriction analysis using well established criteria, and the presence of two indistinguishable strains in two patients was considered one episode of cross-transmission.

Results: During the study period, 121 patients were enrolled into the survey for a total of 2165 days. The ICU-acquired infection rate was 82.6% patients and the incidence density was 46.2‰ patient-days. The occurrence of P. aeruginosa carriage on admission was 1.6% patients. No episode of A. baumannii or S. maltophilia carriage was identified. The ICU-acquired P. aeruginosa, A. baumannii and S. maltophilia associated infection rates were respectively: 35.9%, 13.0% and 12.4% patients. The incidence density were respectively 19.4‰, 7.4‰, 6.9‰ patient-days. ICU-acquired pneumonia was confirmed to be the first infection type (30.0%), followed by bloodstream infections (BSIs) (25.0%), local CVC-related infections (23.0%), urinary tract infections (13.0%), CVC-related BSI (8.0%), and surgical site infections (1.0%). Eighteen P. aeruginosa, one A. baumannii and four S. maltophilia distinct clones were identified by macrorestriction analysis over a total of 162 isolates. The impact of cross-transmission was estimated to be at least 52.4%, thus defining the preventable proportion of all cross-transmission episodes. Two major risk factors were identified: inappropriate management of invasive devices and of antimicrobial usage.

Conclusion: Our study confirms the essential role of epidemiologic surveillance to provide advanced risk-adjusted infection rates as a measure of quality of care.

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:
Back to top