Methicillin-resistant S. aureus (MRSA)

[Clin Infect Dis 2011;52:1-38]

- Incidence of MRSA is significant and in many locations in Canada constitutes ~ 20% of S. aureus isolates.

Screening:

Community - nares

  • Active screening to identify MRSA carriers in the community is NOT warranted but may be considered in specific settings including:

    • individuals with recurrent S. aureus skin infections (≥2 episodes in 6 months) despite enhanced hygiene measures, and in whom eradication is being considered.

    • closed community or family setting with recurrent infection despite enhanced hygiene measures.

Institution - nares and groin

Controversy exists as to whether to screen select high risk patient groups versus high risk settings (presurgical, ICU, hemodialysis). Regardless, the benefit of active screening and isolation is of unproven benefit without strict adherence to hand hygiene and consistent use of contact precautions.

Decolonization:
  • Decolonization regimens of limited success as recolonization is frequent (up to 75% at one year post decolonization).

  • Success of decolonization is much less if extranasal colonization, presence of active skin infection, or presence of indwelling catheters/tubes.

  • Prolonged/repeated use of mupirocin may lead to significant mupirocin resistance.

Therefore decolonization should only be considered in the following circumstances:

  • recurrent CA-MRSA skin infections (≥ 2 episodes in 6 months) despite enhanced hygiene measures and with no evidence of re-exposure.

  • outbreaks in selected closed communities or family settings despite enhanced hygiene measures

Suggested decolonization regimen (only for infants > 1 month old and children):

Empiric Therapy Dose Duration
Mupirocin 2% bid intranasally 5-10 days
+/-    
[Chlorhexidine 2-4% full body wash daily 5-14 days
or    
Dilute bleach bath 1 tsp per gallon of bath water or or 1/4 cup per quarter bath]  15 minutes 2x/week x 3 months

If topical regimens above unsuccessful, repeat topical regimen with systemic antibiotics.

2 active systemic antibiotics:

Empiric Therapy Dose Duration
Rifampin 20mg/kg/d PO div bid 7 days
+    
TMP/SMX 6-10mg TMP/kg/d PO div bid 7 days