Prevalence of Methicillin-Resistant Staphylococcus aureus Colonization in Residents and Staff in Nursing Homes in Northern Ireland

OBJECTIVES: To determine the prevalence of, and factors associated with, methicillin-resistant Staphylococcus aureus (MRSA) colonization in residents and staff in nursing homes in one geographically defined health administration area of Northern Ireland.
DESIGN: Point prevalence study.
SETTING: Nursing homes.
PARTICIPANTS: Residents and staff in nursing homes.
MEASUREMENTS: Nasal swabs were taken from all consenting residents and staff. If relevant, residents also provided urine samples, and swabs were taken from wounds and indwelling devices.
RESULTS: A total of 1,111 residents (66% of all residents) and 553 staff (86% of available staff) in 45 nursing homes participated. The combined prevalence rate of MRSA in the resident population was 23.3% (95% confidence interval (CI)=18.8–27.7%) and 7.5% in staff (95% CI=5.1–9.9%). Residents who lived in nursing homes that were part of a chain were more likely to be colonized with MRSA (odds ratio (OR)=1.91, 95% CI=1.21–3.02) than those living in independently owned facilities. Residents were also more likely to be colonized if they lived in homes in which more than 12.5% of all screened healthcare staff (care assistants and nurses) were colonized with MRSA (OR=2.46, 95% CI=1.41–4.29) or if they lived in homes in which more than 15% of care assistants were colonized with MRSA (OR=2.64, 95% CI=1.58–4.42).
CONCLUSION: The findings suggest that there is substantial colonization of MRSA in nursing home residents and staff in this one administrative health area. Implementation of infection control strategies should be given high priority in nursing homes.