What is the recommended approach for MRSA (Methicillin-resistant Staphylococcus aureus) decolonization?

MRSA Decolonization

MRSA decolonization should NOT be performed routinely in asymptomatic carriers, but is specifically indicated for patients with recurrent skin and soft tissue infections despite optimized hygiene measures, or when ongoing household transmission is documented. 1, 2

When to Consider Decolonization

Decolonization is appropriate only in these specific scenarios:

• Recurrent MRSA 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 implementing hygiene interventions 1, 2
• Following treatment of active infection in symptomatic patients, nasal decolonization may be considered 3

Do not perform routine decolonization in asymptomatic MRSA carriers without these specific indications. 2, 3

Recommended Decolonization Protocol

Standard Regimen (First-Line)

Nasal decolonization with mupirocin 2% ointment applied to both anterior nares twice daily for 5-10 days 1, 2, 4

Enhanced Regimen (For Recurrent Cases)

Combine nasal mupirocin with body decolonization using one of these options:

• Chlorhexidine gluconate 4% body wash daily for 5-14 days 1, 2
• Dilute bleach baths: 1 teaspoon per gallon of water (or ¼ cup per ¼ tub/13 gallons) for 15 minutes twice weekly for 3 months 1, 2

The combination approach (mupirocin plus chlorhexidine or bleach baths) is more effective than mupirocin alone for recurrent infections. 5, 6

Essential Concurrent Hygiene Measures

These must be implemented alongside any decolonization regimen:

• Cover all draining wounds with clean, dry bandages 1, 3
• Hand hygiene with soap and water or alcohol-based sanitizer after touching infected areas or potentially contaminated items 1, 2
• Avoid sharing personal items (razors, towels, linens) that contact skin 1, 2
• Clean high-touch surfaces (doorknobs, counters, bathtubs, toilet seats) with standard commercial cleaners 1, 2

Household Contact Management

When household transmission is suspected or documented:

• Evaluate all symptomatic contacts for active MRSA infection and treat infections first 1, 3
• Consider decolonization of asymptomatic household contacts only when ongoing transmission is documented despite hygiene measures 1, 2, 3
• Treating both patient and household contacts together results in fewer recurrences than treating the patient alone 3

Role of Cultures

Screening cultures are NOT routinely recommended in most decolonization scenarios:

• Pre-decolonization cultures are unnecessary if at least one prior infection was documented as MRSA 1, 2
• Post-decolonization surveillance cultures are not recommended in the absence of active infection 1, 2

The exception: Because mupirocin resistance occurs with greater frequency in MRSA, testing MRSA populations for mupirocin susceptibility prior to use is appropriate using standardized methods. 4

Critical Pitfalls and Caveats

Mupirocin Resistance

• High-level mupirocin resistance (MIC ≥512 mcg/mL) has been reported with increasing frequency in MRSA isolates 1, 4
• Mupirocin resistance is associated with treatment failure (relative risk 9.4) 5
• Avoid prolonged or indiscriminate use to prevent resistance development 3, 7
• Mupirocin resistance occurs more frequently in methicillin-resistant than methicillin-susceptible staphylococci 4

Limited Efficacy Evidence

• Mupirocin effectively reduces nasal colonization but has not conclusively been shown to prevent infections in community settings 1, 3
• Decolonization provides only temporary clearance, with recolonization occurring after discontinuation 2, 8
• Chlorhexidine alone appears ineffective and has only transient effects on colonization 1

Special Population Warnings

• Never use hexachlorophene in children under 2 months of age due to risk of neurological complications 2

Alternative Approaches for Difficult Cases

When standard decolonization fails:

• Oral antibiotics (rifampin plus doxycycline or trimethoprim-sulfamethoxazole) may be considered in conjunction with topical agents when all other decolonization attempts have been exhausted 9, 7, 5
• Oral vancomycin for intestinal colonization and cotrimoxazole for urinary tract colonization may be added to the regimen 6
• A highly effective regimen combining mupirocin, chlorhexidine mouth rinse, full-body chlorhexidine wash, with targeted oral antibiotics for specific colonization sites achieved 87% success rates 6

Algorithmic Approach

1. Confirm indication: Recurrent SSTI despite hygiene OR ongoing household transmission
2. Implement hygiene measures first (wound care, hand hygiene, environmental cleaning)
3. If hygiene measures fail, initiate decolonization:
   • Start with mupirocin 2% nasal ointment twice daily for 5-10 days
   • For recurrent cases, add chlorhexidine body wash or bleach baths
4. Evaluate and treat household contacts if transmission is documented
5. If decolonization fails, consider oral antibiotics in combination with topical agents
6. Do not perform routine surveillance cultures after decolonization