Prevalence of methicillin-resistant Staphylococcus aureus carriage at the time of admission in two acute geriatric wards

Studies on methicillin-resistant Staphylococcus aureus (MRSA) in the elderly have been concerned with patients hospitalized in nursing homes or long-term care facilities. Our objective was to estimate the prevalence of MRSA at the time of admission in two acute geriatric wards with high endemic MRSA incidence in a French teaching hospital. A prospective screening of MRSA carriers was conducted by swabbing nares and wounds during five weeks for all patients on the day of admission. For each patient demographic, administrative, clinical and therapeutic data were recorded. Their associations with MRSA carriage were studied by logistic regression analysis. On the day of admission, 35 patients (14.6%) were MRSA carriers. Variables independently associated with carriage were hospitalization within the six last months (OR = 4.64; P<0.001) and the existence of wounds or bedsores (OR=2.864; P=0.02). The high prevalence of MRSA carriage at the time of admission could explain in part the high incidence of MRSA in these wards. A systematic selective screening targeted on patients with high risk of carriage should be helpful to implement barrier precautions and reduce cross-transmission.