What is the treatment for Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization?

Treatment of MRSA Nasal Colonization

Routine decolonization of asymptomatic MRSA nasal carriers is NOT recommended; treatment should be reserved for specific clinical scenarios including recurrent skin infections despite hygiene measures or ongoing household transmission. 1

When to Treat MRSA Nasal Colonization

Decolonization should only be considered in these situations:

• Recurrent skin and soft tissue infections (SSTI) that persist despite optimizing wound care and hygiene measures 1
• Ongoing transmission among household members or close contacts despite hygiene interventions 1
• Following treatment of active infection in symptomatic patients, nasal decolonization may be considered 1

Do NOT routinely screen or treat asymptomatic carriers without one of these indications. 1

Recommended Decolonization Regimen

When decolonization is indicated, use one of these approaches:

Option 1: Mupirocin Alone

• 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 courses, maintaining decolonization for at least 4 weeks 3
• Eliminates nasal colonization in approximately 90-94% of patients 3, 4

Option 2: Combined Decolonization (Preferred for Recurrent Cases)

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

Essential Concurrent Measures

Decolonization must be combined with reinforced hygiene practices: 1

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

Household Contact Management

• Evaluate symptomatic contacts and treat active infections first, then consider decolonization 1
• Asymptomatic household contacts may be considered for decolonization when ongoing transmission is documented 1
• Recent evidence suggests treating both patient and household contacts together results in fewer recurrences than treating the patient alone 1

Important Limitations and Caveats

Screening cultures are NOT routinely recommended: 1

• Pre-decolonization cultures are unnecessary if prior MRSA infection was documented 1
• Post-decolonization surveillance cultures are not recommended in absence of active infection 1

Evidence limitations: 1

• Mupirocin effectively reduces nasal colonization but has NOT conclusively been shown to prevent infections in community settings 1
• One trial in military personnel found mupirocin did NOT reduce subsequent skin infections despite clearing nasal carriage 1
• Recolonization is common within several months despite initial clearance 5

Resistance concerns: 1, 2, 5

• High-level mupirocin resistance has been reported in some community settings 1
• Prolonged or indiscriminate use should be avoided to prevent resistance development 2, 6

Alternative for Persistent Recurrent Infections

For particularly persistent recurrent furunculosis after failed decolonization attempts:

• Clindamycin 150 mg orally daily for 3 months decreases subsequent infections by approximately 80% 2