Community-associated MRSA

Overview

Meticillin-resistant Staphylococcus aureus (MRSA) is a significant bacterial pathogen, mainly associated with the secondary and tertiary healthcare environments, commonly termed healthcare-associated MRSA (HA-MRSA). More recently, a new type of MRSA has emerged, community-associated MRSA (CA-MRSA).

CA-MRSA is commonly associated with individuals in the community who have no risk factors for the acquisition of HA-MRSA such as hospitalisation or indwelling devices. CA-MRSA and HA-MRSA are both forms of MRSA, but have distinct epidemiological and microbiological characteristics, which enable them to be differentiated.¹

While HA-MRSA affects neonates and the elderly, CA-MRSA usually affects young, healthy individuals who have no risk factors for HA-MRSA. HA-MRSA causes bacteraemia or endocarditis and wound infections, symptomatic infections of respiratory and urinary tracts, whereas in CA-MRSA it is mainly skin which is involved - abscesses, cellulitis, furunculosis, severe skin and soft tissue infections may be observed. A skin lesion caused by CA-MRSA may mimic a spider-bite. Therefore, where a patient has returned from an area where spider bites are common,CA-MRSA should be considered and if in doubt, a swab should be cultured.