The MRSA point-prevalence: an important tool in the infection control programme

Abstract number: 1733_809

Chaberny I., Bindseil A., Mattner F., Gastmeier P.

Background: Due to the enormous increase in the number of MRSA-patients, an extended admission screening on ICUs and surgical wards was implemented at the Hannover Medical university hospital since July 2004 (18.4 nares cultures per 1,000 patient days).

Objectives: To determine the prevalence of MRSA and Panton-Valentine leukocidin (PVL) among inpatients, to identify other patients at risk for MRSA colonisation and to evaluate the compliance with the established admission screening.

Methods: Inpatients were screened by cultures from nose, throat and broken skin in a point-prevalence survey in the year 2005. S. aureus isolates were tested for oxacillin susceptibility and for PVL. MRSA were tested for antimicrobial susceptibility and were analysed by staphylococcal protein A (spa) typing.

Results: Of 510 inpatients, 145 (28%) were S. aureus carriers. 27 (19% of all S. aureus isolates) were MRSA, i.e. 5.3% of all inpatients were MRSA carriers (95% CI: 3.49; 7.70) which was the MRSA prevalence. With 67% was the spa type t032 or so called ``Barnimer'' strain predominant followed by t001 (15%), t004 (4%), t008 (4%), t022 (4%) and t067 (4%). The PVL gene was present in one (0.2%) methicillin-susceptible strain. Compared to our MRSA database the MRSA status of 37% of the patients (pts) was unknown (ten out of 27 pts), e.g. in 2.0% (ten out of 510 pts) of all inpatients the MRSA colonisation was identified for the first time. In three out of these ten cases the compliance with the established admission screening had failed. Although the admission screening had previously led to negative results concerning three other patients, a nosocomial acquisition was identified. Four other newly MRSA patients had been detected on wards without a routinely admission screening (three cases on neurological and one case on an internal medicine ward).

Conclusion: The results of our study pointed to a 5.3% prevalence of MRSA, which proved higher than our previous observations had suggested and it pointed to a 0.2% prevalence of PVL-positive S. aureus. Despite an extended admission screening practice 37% of all MRSA-positive inpatients had been missed. The neurological patients were identified as a further risk group for admission screening and were included in the established admission screening practice. In addition, a weekly surveillance cultures practice seems to be useful in order not to miss further MRSA cases.

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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