Prevalence and risk factors for meticillin-resistant Staphylococcus aureus in an acute care hospital and long-term care facilities located in the same geographic area

Abstract

To determine the prevalence and risk factors (RF) for methicillin-resistant Staphylococcus aureus (MRSA) during stay in 1 acute care hospital (ACH) and 4 long-term care facilities (LTCF). After obtaining the informed consent, nasal and skin ulcer swabs were taken and a survey was conducted to determine RF for MRSA. Six hundred and ninety nine patients were included, 413 LTCF and 286 ACH patients and MRSA prevalence were 22.5% and 7.3% respectively. MRSA was located in the nares, skin ulcers, and in both in 61.4%, 21.1%, and 17.5%. Among MRSA carriers, 81% of the ACH and 66.7% of the LTCF patients were only colonized. The multivariate analysis for the ACH revealed the following factors to be associated with MRSA: referral from an LTCF (OR 4.84), pressure ulcers (OR 4.32), a Barthel score < 60 (OR 2.60), and being male (OR 5.21). For the LTCF: urinary catheterisation (OR 3.53), pressure ulcers (OR 2.44), other skin lesions (OR 2.64), antibiotic treatment in ≤ 6 months, (OR 2.23), previous MRSA colonization (OR 2.15), and a Barthel score <20 (OR 1.28). Molecular typing identified 2 predominant clones Q, P, present in all centres. No relationship was found between clones and antibiotic susceptibility.

In conclusion: MRSA prevalence is high in all centres but is 3 times greater in LTCF. The risk factors most strongly associated with MRSA were pressure ulcers and a stay in an LTCF. We propose preventive isolation in these cases.