MRSA Nasal Colonization: Treatment Recommendations
For asymptomatic patients with positive MRSA nasal swabs, routine decolonization is NOT recommended unless specific high-risk criteria are met. 1
When to Consider Decolonization
Decolonization should only be pursued in the following situations:
- Recurrent skin and soft tissue infections (SSTIs) despite optimized wound care and hygiene measures 1
- Ongoing household transmission among close contacts despite hygiene interventions 1
- Pre-surgical prophylaxis in certain high-risk populations (primarily orthopedic or cardiac surgery) 1
Do NOT routinely decolonize asymptomatic carriers discovered incidentally, as evidence does not support preventing first-time infections in community settings. 1
Recommended Decolonization Regimen
When decolonization is indicated, use a combination approach rather than mupirocin alone:
Primary Regimen
- Intranasal mupirocin 2% ointment applied to both anterior nares twice daily for 5-10 days 1
- PLUS topical body decolonization with one of the following:
Critical Implementation Details
- Mupirocin alone is insufficient for sustained decolonization in the MRSA era; combination therapy is superior 1
- Apply mupirocin by inserting a pea-sized amount into each nostril and pressing nostrils together to distribute 1
- For bleach baths, ensure proper dilution to avoid skin irritation; provide clear written instructions 1
- Chlorhexidine wipes used alone (without mupirocin) are ineffective 1
Essential Concurrent Hygiene Measures
Decolonization must be combined with reinforced hygiene practices:
- Keep any draining wounds covered with clean, dry bandages 1
- Daily bathing with soap and water or alcohol-based hand gel, especially after touching infected areas 1
- Avoid sharing personal items (razors, towels, linens) that contact skin 1
- Clean high-touch surfaces (doorknobs, counters, toilet seats) with commercial cleaners 1
- Wash towels, sheets, and clothing daily during decolonization period 1
Household Contact Management
- Symptomatic contacts: Evaluate and treat active infections first, then consider decolonization 1
- Asymptomatic household contacts: May consider decolonization if ongoing transmission occurs despite hygiene measures 1
- Recent pediatric data suggests treating both patient and household contacts simultaneously reduces recurrence more effectively than treating the patient alone 1
Important Limitations and Caveats
Mupirocin Resistance Concerns
- Mupirocin resistance is increasing in some MRSA populations, with rates up to 50% in certain settings 2, 3
- High-level mupirocin resistance results in treatment failure rates of 73% 3
- Consider local resistance patterns before implementing widespread decolonization programs 1, 3
- Repeated or prolonged mupirocin use may select for resistant strains 1
Evidence Limitations
- No randomized trials demonstrate that decolonization prevents MRSA infections in community settings 1
- One military trial showed mupirocin did NOT reduce subsequent skin infections despite clearing nasal colonization 1
- Most supporting evidence comes from healthcare settings (surgical patients, dialysis) rather than community carriers 1
- Recolonization commonly occurs within weeks to months after stopping treatment 4, 5
When Decolonization Fails
If infections recur despite decolonization:
- Re-evaluate for underlying conditions (hidradenitis suppurativa, pilonidal disease, foreign bodies) 1
- Consider neutrophil function testing if recurrent abscesses began in early childhood 1
- Repeat decolonization may be attempted, but efficacy diminishes with repeated courses 1
What NOT to Do
- Do NOT use oral antibiotics for asymptomatic nasal colonization; no evidence supports this approach and it promotes resistance 1
- Do NOT screen asymptomatic individuals outside of specific outbreak or pre-surgical settings 1
- Do NOT use hexachlorophene in infants under 2 months due to neurotoxicity risk 1
- Do NOT rely on chlorhexidine wipes alone without mupirocin; this approach has failed in trials 1