Table 1—

Typical differences between HA-MRSA and CA-MRSA

Typical patientElderly, debilitated and/or critically or chronically illYoung healthy people, students, professional athletes and military personnel
Infection siteOften bacteraemia with no obvious source of infectionAlso surgical wounds, open ulcers, i.v. lines and catheter urinesMay cause ventilator-associated pneumoniaPredilection for skin and soft tissue producing cellulitis and abscessesMay cause necrotising community-acquired pneumonia, septic shock or bone and joint infections
TransmissionWithin healthcare settings; little spread among household contactsCommunity acquired; may spread in families and sports teams
Clinical setting of diagnosisIn an in-patient setting, but increasingly HA-MRSA infections in soft tissue and urine are occurring in primary careIn an outpatient or community setting
Medical historyHistory of MRSA colonisation, infection or recent surgery; admission to a hospital or nursing home; antibiotic use; dialysis, permanent indwelling catheterNo significant medical history or healthcare contact
Virulence of infecting strainCommunity spread is limited PVL genes usually absentCommunity spread occurs easily PVL genes often present, predisposing to necrotising soft tissue or lung infection
Antibiotic susceptibilityOften multiresistant with the result that the choice of agents is often very limitedGenerally susceptible to more antibiotics than HA-MRSA
  • HA-MRSA: hospital-associated methicillin-resistant Staphylococcus aureus; CA-MRSA: community-acquired methicillin-resistant Staphylococcus aureus. PVL: Panton–Valentine leukocidin. Reproduced from 17 with permission from the publisher.