MRSA is usually transmitted from patient-to-patient via the hands of healthcare workers following direct contact with a person who has a purulent lesion or is an asymptomatic carrier. Colonized health care workers with dermatitis [or paronychia] are especially likely to transmit MRSA to patients. Transmission by the airborne route is much less likely to occur except in burn units or dermatology units where aerosolized MRSA may contaminate environmental surfaces.

Reservoirs - Colonized and infected patients are the major reservoirs of MRSA. MRSA has been isolated from environmental surfaces including floors, sinks, work areas, tourniquets used for blood drawing, and blood pressure cuffs. Although MRSA has been isolated from environmental surfaces (e.g., floors, medical equipment), such surfaces are not the most likely source of transmission. However, environmental surfaces should be disinfected routinely to reduce the bacterial load.