Carriage of Methicillin-Resistant Staphylococcus aureus Among Hospital Employees: Prevalence, Duration, and Transmission to Households

Abstract

Objective: To assess the prevalence and duration of methicillin-resistant Staphylococcus aureus(MRSA) carriage among hospital employees and transmission to their households. Design: A point-prevalence survey of MRSA carriage (nasal swabbing) of staff and patients throughout the hospital; a prevalence survey of MRSA carriage in 2 medical wards, with carriers observed to estimate carriage duration; and evaluation of transmission to MRSA-positive workers' families. All MRSA isolates were analyzed by pulsed-field gel electrophoresis. During the study, no MRSA outbreak was detected among hospitalized patients. Setting: A 600-bed, public tertiary-care teaching hospital near Paris. Results: Sixty MRSA carriers were identified among 965 healthcare providers (prevalence, 6.2%; CL,, 4.7%-7.7%). Prevalence was higher in staff from clinical wards than from elsewhere (9.0% vs 2.1%;P< .0001). Identity of isolates from employees and patients varied from 25% in medical wards to 100% in the long-term-care facility. MRSA carriage was identified in 14 employees from 2 medical wards (prevalence, 19.4%; CI 95, 10.3%-28.5%). Prevalence depended on the length of service in these wards. Transmission to households was investigated in 10 MRSA-positive workers' families and was found in 4. All isolates from each family were identical. Conclusions: Few data are available concerning the prevalence of MRSA carriers among hospital employees in the absence of an outbreak among patients. MRSA transmission between patients and employees likely depends on the frequency and duration of exposure to MRSA-positive patients and infection control measures employed. Frequent transmission of MRSA from colonized healthcare workers to their households was documented.