Mortality among methicillin-resistant Staphylococcus aureus carriers in long-term care facilities

Little is known about the natural course of patients with chronic stable illnesses colonized with methicillin-resistant Staphylococcus aureus (MRSA). The aim is to determine the impact of MRSA colonization in mortality among long-term health care facility (LTHCF) residents.

A multicenter, prospective, observational study was designed. Residents in 4 LTHCFs were classified according to MRSA carriage status and followed for 12 months. Treatment consisted of 5 days of nasal mupirocin in MRSA carriers.

Ninety-three MRSA-carriers among 413 residents were identified. Thirty-one MRSA-colonized patients died during the study period, 11 of whom from an infectious disease. Independent predictors of their higher mortality rates included heart failure, current neoplasm, MRSA carriage and COPD at 3 months and these same factors plus stroke, Bar-thel index <40, pressure ulcers, and older age at 12 months. MRSA-persistence was 35% and 62.5% at 3 and 12 months, respectively.

MRSA colonization among frail LTHCFs residents is highly prevalent, and is associated with higher mortality. Despite treatment of MRSA carriers, many remained colonized. Factors that promote persistence of MRSA colonization, and the impact of their modification on mortality rates in these patients, need further investigation.