Carriage of methicillin-resistant Staphylococcus aureus in home care settings: prevalence, duration, and transmission to household members.

BACKGROUND: Several studies have documented prolonged colonization with hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) after hospital discharge. However, information is lacking about factors associated with prolonged MRSA colonization and MRSA transmission to household contacts.

METHODS: From February 2003 to March 2004, adult inpatients (except obstetric patients) were screened for MRSA carriage before discharge to home health care. Bivariate and multivariate analyses were performed to evaluate rates and risk factors of MRSA carriage at discharge, MRSA clearance within 1 year, and MRSA transmission to household contacts.

RESULTS: We identified MRSA in 191 of the 1501 patients screened before discharge to home health care (12.7%). Of the 148 patients with MRSA who were observed, 75 cleared the organism within 1 year, with an estimated median time to clearance of 282 days (95% confidence interval [CI], 233-313 days). Clearance of MRSA was associated with self-sufficiency in daily activities (hazard ratio, 0.63; 95% CI, 0.40-1.00) (P = .049). Of the 188 included household contacts, 36 acquired MRSA (19.1%). Factors associated with household MRSA acquisition were older age (adjusted odds ratio, 1.71 per life decade; 95% CI, 1.32-2.21) (P = .001) and participation in the health care of the index patient (adjusted odds ratio, 3.58; 95% CI, 1.33-9.62) (P = .01).

CONCLUSIONS: Hospital-acquired MRSA carriage was common at discharge to home health care and was frequently prolonged. Transmission occurred in nearly 20% of household contacts and was associated with older age and participation in health care of the index patient. Household contacts should apply infection control measures similar to those recommended in the hospital setting.