Comparison of systematic versus selective screening for methicillin-resistant Staphylococcus aureus carriage in a high-risk dermatology ward

OBJECTIVE: To compare two strategies for screening methicillin-resistant Staphylococcus aureus (MRSA) carriers in a high-risk dermatology ward: systematic screening of all admitted patients versus selective screening of patients at risk. DESIGN: The two strategies were applied prospectively during two consecutive periods. In period A (8.5 months), only patients transferred from other wards, or with a history of prior hospitalization, or presenting chronic wounds or disease with denuded skin were considered at high risk of MRSA carriage and sampled. In period B (7.5 months), all admitted patients were systematically screened. End-points were the number of patients having a MRSA-positive screening sample on admission during period B and having none of the risk factors used in period A, the rate of imported MRSA cases. and the rate of acquired cases. SETTING: A 1,032-bed university hospital with a 19-bed inpatient dermatology ward, a referral center for toxic epidermal necrolysis and severe extensive dermatoses. PATIENTS: The study included 729 dermatology inpatients (370 in period A and 359 in period B). RESULTS: During period A screening samples were obtained on admission for 30% of patients (77% of the patients at risk) and identified 25 MRSA carriers. During period B, 90.5% of admitted patients were screened, and 26 MRSA carriers were detected on admission; all of these patients belonged to at least one predefined category at risk for carriage. Overall rates of imported and acquired cases were similar between the two periods (6.8% vs 7.5%, and 2.9% vs 2.4%, respectively). CONCLUSIONS: A screening strategy targeted to patients at risk of harboring MRSA has similar sensitivity and is more cost-effective than a strategy of systematic screening to identify MRSA carriers on admission.