Risk factors/features suggestive of community-aquired MRSA (CA-MRSA)

• community-associated MRSA
  • if 'spider bite' lesions are present, the possibility of CA-MRSA or Panton–Valentine leucocidin (PVL)-positive methicillin sensitive Staphylococcal aureus (MSSA) infection should be considered and appropriate investigation and management instituted
    • typical of cutaneous CA-MRSA infections
      • spontaneous appearance of a raised tender red lesion, which may progress to develop a necrotic centre
  • if there is a history of recurrent abscesses or household clusters of infection, the possibility of CA-MRSA or PVL-positive MSSA infection should be considered and appropriate investigation and management instituted
  • if there has been a prior poor response to ß-lactam therapy, the possibility of CA-MRSA or PVL-positive MSSA infection should be considered and appropriate investigation and management instituted
  • if there is a history of exposure to one or more antibiotics in the past year, especially quinolones or macrolides, the possibility of CA-MRSA infection should be considered and appropriate investigation and management instituted
    • risk factors for CA-MRSA include:
      • children <2 years old
      • athletes (mainly contact-sport participants)
      • injection drug users
      • men who have sex with men
      • military personnel
      • inmates of correctional facilities, residential homes or shelters
      • vets, pet owners and pig farmers
      • patients with post-flu-like illness and/or severe pneumonia
      • patients with concurrent skin and soft tissue injury
      • history of colonization or recent infection with CA-MRSA
      • history of antibiotic consumption in the previous year, particularly quinolones or macrolides
  • cultures should be taken from septic sites if:
    • CA-MRSA is suspected because of the risk assessment based on clinical presentation, treatment factors and other risk factors
    • there are recurrent furuncles or abscesses (two or more in 6 months)
    • there is a history of spread in the family or to others, e.g. sporting contacts (the information may be available from the public health/infection control team)
    • there is severe infection (extensive or progressive disease with evidence of systemic sepsis), the patient should be hospitalized and a skin/abscess culture and blood culture should be taken
  • do not take cultures routinely from patients presenting with minor SSTIs and without a history of previous MRSA
  • do not routinely aspirate material for culture from cellulitis in the absence of discharge or broken skin

Reference:

• (1) Nathwani D et al. Guidelines for UK practice for the diagnosis and management of methicillin-resistant Staphylococcus aureus (MRSA) infections presenting in the community.J Antimicrob Chemother. 2008 May;61(5):976-94.