What is the recommended decolonization treatment for a patient identified as a nasal carrier of Methicillin-resistant Staphylococcus aureus (MRSA)?

MRSA Nasal Carrier Decolonization

When to Decolonize

Do not routinely decolonize asymptomatic MRSA nasal carriers—reserve treatment for specific high-risk scenarios only. 1, 2, 3

Decolonization is indicated in these specific situations:

• Recurrent skin and soft tissue infections that persist despite optimized wound care and hygiene measures 1, 2, 3
• Ongoing household transmission among close contacts despite hygiene interventions 1, 2, 3
• Pre-operative preparation before high-risk surgeries (cardiac, orthopedic, or procedures involving prosthetic material), ideally completed 1-2 weeks before the procedure 1, 4
• Following treatment of active MRSA infection in symptomatic patients 3, 4

Standard Decolonization Protocol

The gold standard regimen is mupirocin 2% ointment applied to both anterior nares twice daily for 5 days (10 doses total). 1, 4

For Nasal-Only Carriers:

• Mupirocin 2% ointment to both anterior nares twice daily for 5 days 1, 4
• This is highly effective for nasal-only MRSA carriers 5

For Recurrent Cases or Extra-Nasal Colonization:

Combine nasal and body decolonization for maximum effectiveness. 1, 2, 3

• Mupirocin 2% ointment to both anterior nares twice daily for 5-10 days 1, 3, 4
• PLUS one of the following body decolonization methods:
  • Chlorhexidine gluconate 4% body wash daily for 5-14 days 1, 2, 3
  • OR dilute bleach baths: ¼ to ½ cup bleach per full bathtub (or 1 teaspoon per gallon of water), 15 minutes twice weekly for up to 3 months 1, 3, 4

The combination of mupirocin plus chlorhexidine is supported by the strongest evidence, particularly from the landmark Bode et al. study showing significant reductions in surgical site infections. 1

Pre-Operative Timing

Complete the 5-day mupirocin course as close as possible to surgery, ideally within 1-2 weeks before the procedure. 1, 4

• If the course cannot be completed preoperatively, finish it postoperatively 1, 4
• For elective surgery, consider postponing the procedure to complete decolonization if feasible and posing no additional patient risks 1, 4
• The strongest evidence exists for cardiac and orthopedic surgeries, with a 45% reduction in postoperative S. aureus infections 1

Essential Concurrent Hygiene Measures

Decolonization fails without rigorous hygiene—these measures are non-negotiable. 1, 2, 3

• Keep all draining wounds covered with clean, dry bandages 2, 3, 4
• Practice hand hygiene with soap and water or alcohol-based sanitizer after touching infected areas or potentially contaminated items 2, 3, 4
• Avoid sharing personal items (towels, razors, clothing, linens) that contact skin 1, 2, 3
• Clean high-touch surfaces (counters, doorknobs, bathtubs, toilet seats) daily with standard commercial cleaners 2, 3, 4
• Treat interdigital toe space infections or maceration to eliminate colonization reservoirs 3, 4
• Wash towels, sheets, and clothing in hot water 2

Household Contact Management

Recent evidence shows that treating both the patient and household contacts together results in significantly fewer recurrences than treating the patient alone. 2, 4

• Evaluate all symptomatic contacts first and treat any active infections before considering decolonization 2, 3, 4
• Asymptomatic household contacts should receive decolonization only when ongoing transmission is documented despite hygiene measures 2, 3, 4
• Use the same decolonization protocol for household contacts as for the index patient 1, 2

Monitoring and Follow-Up

Do not perform routine surveillance cultures before or after decolonization in the absence of active infection. 1, 2, 4

• Pre-decolonization screening cultures are unnecessary if at least one prior infection was documented as MRSA 1, 2, 4
• Post-decolonization surveillance cultures are not recommended unless there is active infection 1, 2, 4
• Recolonization occurs in 40-60% of patients within 3 months after decolonization, so continuous reinforcement of hygiene measures is critical 2

Critical Pitfalls to Avoid

Mupirocin resistance is a real concern—avoid prolonged or indiscriminate use. 1, 3

• High-level mupirocin resistance has been reported in some community settings 1, 3
• Monitor local resistance patterns to mupirocin 2
• Do not use mupirocin for routine decolonization of asymptomatic carriers without specific indications 1, 2, 3
• Hexachlorophane should not be used in children under 2 months of age due to risk of neurological complications 2

Evidence Quality and Nuances

The strongest evidence for decolonization comes from pre-operative settings, particularly the Bode et al. study showing significant reductions in surgical site infections with mupirocin plus chlorhexidine. 1 However, evidence for community-acquired MRSA decolonization is more limited. 1 A high-quality 2019 New England Journal of Medicine trial demonstrated that postdischarge decolonization with chlorhexidine and mupirocin led to a 30% lower risk of MRSA infection compared to education alone, with 84.8% of MRSA infections leading to hospitalization. 6 This underscores the clinical significance of successful decolonization in high-risk populations.

For extra-nasal colonization, addition of systemic antibiotics (particularly rifampin-based combinations) may increase success rates, though evidence is heterogeneous. 5 This should be reserved for cases where topical therapy alone has failed and all other measures have been exhausted. 7

Success rates for decolonization are modest—approximately 39% in one real-world study—but even this partial success significantly reduced infection rates (0% vs 4.3% in failures). 8 The effectiveness justifies continuation of this strategy despite the marginal success rate, particularly given the low cost and safety profile of topical decolonization. 1, 8