What is the best way to use nasal mupirocin for a patient with Methicillin-resistant Staphylococcus aureus (MRSA) colonization?

Nasal Mupirocin for MRSA Colonization

Direct Recommendation

Apply mupirocin 2% ointment to the anterior nares twice daily for 5-10 days, but only use this decolonization strategy in specific clinical scenarios—not routinely for all asymptomatic MRSA carriers. 1, 2

When to Use Nasal Mupirocin Decolonization

Decolonization should be reserved for specific situations, not used routinely:

• Recurrent skin and soft tissue infections that persist despite optimizing wound care and hygiene measures 1, 2
• Ongoing transmission among household members or close contacts despite hygiene interventions 1, 2
• Following treatment of active MRSA infection in symptomatic patients 1, 2

Do not perform routine decolonization of asymptomatic MRSA nasal carriers outside these scenarios. 2

Exact Application Protocol

Standard Regimen

• Mupirocin 2% ointment applied to anterior nares twice daily for 5-10 days 1, 2
• The 10-dose regimen (twice daily for 5 days) is superior to shorter 6-dose regimens, maintaining decolonization for at least 4 weeks (89.5% vs 68% success rate) 3

Enhanced Regimen for Recurrent Cases

For patients with persistent recurrences, use a combined approach:

• Mupirocin 2% ointment to anterior nares twice daily for 5-10 days 2
• PLUS topical body decolonization with chlorhexidine for 5-14 days 1, 2
• OR dilute bleach baths (1/4 to 1/2 cup bleach per full bathtub) 2

Essential Concurrent Hygiene Measures

Decolonization must be paired with these interventions:

• Keep draining wounds covered with clean, dry bandages 2
• Hand hygiene with soap and water or alcohol-based gel after touching infected areas 2
• Avoid sharing personal items (razors, linens, towels) that contacted infected skin 1
• Clean high-touch surfaces (counters, doorknobs, bathtubs, toilet seats) with commercial cleaners 1, 2
• Treat interdigital toe space infections/maceration to reduce colonization reservoirs 2

Household Contact Management

When ongoing transmission is documented:

• Evaluate symptomatic contacts first and treat any active infections 2
• Consider decolonization of asymptomatic household contacts using the same mupirocin regimen 1, 2
• Treating both patient and household contacts together results in fewer recurrences than treating the patient alone 2

Critical Limitations and Resistance Concerns

When Mupirocin May Fail

• Mupirocin-resistant MRSA shows significantly reduced efficacy: only 27.7% of high-level resistant strains cleared on day 3 versus 78.5% of susceptible strains 4
• High-level mupirocin resistance (MIC >512 µg/mL) is associated with treatment failure 5
• Sustained clearance at 1-4 weeks occurs in 91% with susceptible strains but only 25% with resistant strains 4

Avoiding Resistance Development

• Avoid prolonged or indiscriminate use to prevent resistance development 2, 5
• High-level mupirocin resistance has been reported in community settings 2
• Consider sampling MRSA populations for mupirocin susceptibility before incorporating into infection control programs 4

Evidence Limitations

• Mupirocin effectively reduces nasal colonization but has not conclusively been shown to prevent infections in community settings 2
• Relapses are common within several months even after successful initial clearance 6

What NOT to Do

• Do not perform screening cultures routinely; pre-decolonization cultures are unnecessary if prior MRSA infection was documented 2
• Do not perform post-decolonization surveillance cultures in the absence of active infection 2
• Do not use mupirocin for extensive infections requiring systemic therapy 5