Prevalence of Staphylococcus aureus carriage among asymptomatic nursing home personnel: a pilot study

To determine the carriage rate of Staphylococcus aureus (SA), both methicillin sensitive, and methicillin resistant (MRSA), among employees of a nursing home in the absence of an epidemic.

Observational study.

A 210-bed suburban skilled nursing facility with a low endemic rate of SA infection.

Seventy-three asymptomatic employees recruited in two waves.

Nasal swabs were cultured for SA; DNA strain typing was performed on MRSA isolates from the first wave of recruits.

21 of 73 (29%) cultures were positive for SA. Ten of these 21 (14% of participating employees) had nasal carriage of MRSA. MRSA carriage was not significantly correlated with age, duration of employment, or job type (clinical vs. non-clinical), and DNA strain typing suggested that employee carriage of MRSA was not the result of a common source.

Staphylococcus aureus nasal carriage is common among skilled nursing facility personnel, and MRSA accounts for a substantial proportion of SA carriage among employees, even in the absence of an epidemic. Further research is needed to determine whether the high SA carriage rates among employees reflects work place acquisition, and, if so, whether it poses a hazard to the employees. The low incidence of nosocomial MRSA infections around the time of the study suggests that with usual infection control practices (eg, hand washing), MRSA-colonized caregivers pose little risk to nursing facility residents.