Healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) is associated with severe, invasive disease in hospitalized patients．
Community-associated methicillin-resistant S. aureus (CA-MRSA) is most often associated with skin and soft tissue infections in young, healthy individuals with no recent healthcare exposure.
Though convenient epidemiologic terms, the line between "healthcare-associated" and "community-associated" MRSA is significantly blurred. Patients can develop MRSA colonization in one realm and develop manifestations of infection in another or simply introduce MRSA in the second realm.
Risk factors for infection due to HA-MRSA include antibiotic use, prolonged hospitalization, intensive care, invasive devices, hemodialysis, MRSA colonization, and proximity to others with MRSA colonization or infection.
Additional risk factors for CA-MRSA infection include skin trauma (eg, lacerations, abrasions, tattoos, injection drug use), cosmetic body shaving, incarceration, HIV infection, and sharing equipment that is not cleaned or laundered between users.
MRSA transmission occurs via contact with a colonized individual or a contaminated fomite.