Risk factors for MRSA colonization in dermatologic patients in Germany

Detection of methicillin-resistant Staphylococcus aureus (MRSA) carriage requires well-defined risk factors (RFs). Except for "chronic wounds", RFs are mostly specified in national recommendations. To avoid ineffective and expensive screening, we divided the entity "wounds" into different categories and calculated further RFs in dermatologic patients.

After a surveillance period with general MRSA screening, we correlated MRSA results with wound categories and dermatologically relevant diagnoses. We analyzed the screening efficacy by adding potential new RFs.

Ulcers (pressure, arterial, combined pressure/arterial ulcers, ulcers otherwise unclassified), type 2 diabetes mellitus (DM), and atopic dermatitis (AD) were significantly associated with MRSA carriage. Tumors (subgroup basal and squamous cell carcinoma) were also significantly associated with MRSA carriage but had a protective odds ratio. Differentiation of wound types did not provide added benefit. In all MRSA-positive patients with chronic wounds, other RKI-listed RFs or type 2 DM were found. Screening sensitivity was increased combining classic RFs (except wounds) with type 2 DM and AD.

In dermatologic patients, AD and type 2 DM were identified as new RFs. Distinct wound types were also found to be significant RFs, but differentiated screening offers no benefit. When screening patients according to national recommendations, excluding wounds but including type 2 DM and AD, there is no loss of sensitivity.