501. Evaluation of the Duration of VanA Vancomycin-Resistant Enterococcus faecium (VRE) Carriage in Stools during a Large-Scale Outbreak Occurring in a Region of the Eastern Part of France
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A

Between 2005 and 2008, a large outbreak of VRE colonization initially occurred in the Hospital of Nancy, the tertiary-care teaching hospital of Lorraine, a region of the eastern part of France, and secondarily spread in other facilities of this region; more than 1000 cases were reported and 35 institutions were concerned. Molecular typing has confirmed that all tested carriers were colonized with an identical epidemic strain. During this outbreak, after evidence of VRE carriage in an inpatient, follow-up was recommended, especially after hospital discharge. Monthly rectal screening (RS) was performed at least until 3 consecutive negative results were obtained. Only rectal swabs stained with stools were considered. Data concerning 306 patients were available: 2222 follow-up cultures (mean/patient=7±8; range 2 to 55) were collected over a follow-up of 82 500 days (mean follow-up after the date of the first isolate/patient=270±279d; range 7 to 1330). Among the 82 patients with at least two positive RS results (including first isolate; mean 4 positive RS/patient) followed by one negative RS result, the median duration of carriage (between first and last positive RS) was 42 days (75th percentile=101d; 90th percentile=221d). For 4 patients carriage durations of up to 248 days were observed with more than 15 RS being performed during this follow-up period (max=708d with 25 successive positive RS). Among these 82 patients, 14 (17%) had again one positive RS result following at least two negative RS results; the median duration with negative RS results was 23 days (75th percentile=48d; 90th percentile=62d; max=112d with 9 successive negative RS results). Thus, negative RS results in a known VRE carrier may simply reflect a decrease in the quantity of VRE to an undetectable level. Therefore, if such patient needs to be re-admitted, precautions must be maintained because “relapse” may be observed, especially in the case of re-treatment with antibiotics.
Nejla Aissa, MD1, Sandrine Henard, MD2, Nathalie Jouzeau, Nurse3, Alain Lozniewski, MD, PhD1, Christian Rabaud, MD, PhD4 and  S. Henard, None..
N. Aissa, None..
N. Jouzeau, None..
A. Lozniewski, None..
C. Rabaud, None., (1)Department of Microbiology, University Hospital, Nancy, France, (2)Infectious Diseases Department, University Hospital, Nancy, France, (3)CClin Est, Nancy, France, (4)university hospital center of Nancy