What are the treatment options for a patient identified as a nasal Methicillin-resistant Staphylococcus aureus (MRSA) carrier?

Treatment of Nasal MRSA Carriers

Routine decolonization of asymptomatic nasal MRSA carriers is not recommended; treatment should be reserved for patients with recurrent skin and soft tissue infections (≥2 episodes at different sites over 6 months) or documented ongoing household transmission despite hygiene measures. 1, 2

When Decolonization Is Indicated

Decolonization should only be pursued in specific clinical scenarios:

• Recurrent skin and soft tissue infections that persist despite optimized wound care and hygiene measures (≥2 episodes at different anatomic sites over 6 months) 1, 2
• Ongoing transmission among household members or close contacts despite implementation of hygiene interventions 1, 2
• Following treatment of active infection in symptomatic patients, decolonization may be considered to prevent recurrence 1, 2

The evidence strongly supports avoiding routine decolonization of asymptomatic carriers, as this approach promotes antimicrobial resistance without proven clinical benefit in preventing future infections in community settings. 2, 3

Standard Decolonization Protocol

For Nasal-Only Carriers

Mupirocin 2% ointment applied to both anterior nares twice daily for 5-10 days is the standard first-line regimen. 1, 2, 3

This topical-only approach is highly effective for patients with nasal-only carriage. 4

For Recurrent Cases or Extra-Nasal Colonization

An enhanced combined protocol is more effective:

• Mupirocin 2% ointment to anterior nares twice daily for 5-10 days, PLUS 1, 2
• Chlorhexidine gluconate 2% body wash daily for 5-14 days, OR 1, 2, 3
• Dilute bleach baths (1/4 to 1/2 cup bleach per full bathtub) for 15 minutes twice weekly for up to 3 months 2, 3

For patients with extra-nasal colonization, addition of systemic antibiotics (rifampin plus another antimicrobial agent) likely increases success rates compared to topical therapy alone, though specific regimens remain heterogeneous in the literature. 4

Essential Concurrent Hygiene Measures

These non-antimicrobial interventions are critical and must be implemented alongside any decolonization regimen:

• Keep all draining wounds covered with clean, dry bandages 1, 2, 3
• Hand hygiene with soap and water or alcohol-based gel after touching infected areas or contaminated items 1, 2, 3
• Avoid sharing personal items (towels, razors, clothing) 2, 3
• Clean high-touch surfaces with commercial cleaners regularly 2, 3
• Treat interdigital toe space infections or maceration to reduce colonization reservoirs 2, 3

Household Contact Management Algorithm

Follow this stepwise approach:

1. First, evaluate all symptomatic household contacts and treat any active infections before considering decolonization 1, 2, 3
2. Consider decolonization of asymptomatic household contacts only when ongoing transmission is documented despite hygiene measures 1, 2, 3
3. Treat both patient and household contacts simultaneously when decolonization is indicated, as this results in fewer recurrences than treating the patient alone 2, 3

Critical Pitfalls to Avoid

• Do NOT obtain screening cultures before or after decolonization in the absence of active infection—this promotes resistance without clinical benefit 1, 2, 3
• Do NOT use mupirocin for simple nasal trauma or cuts without signs of infection 3
• Avoid prolonged or indiscriminate mupirocin use as high-level mupirocin resistance has been reported in community settings 1, 2, 3
• Do NOT expect long-term eradication in high MRSA prevalence settings—recolonization occurs in 40-60% of patients within 3 months 3, 4
• Do NOT use hexachlorophane in children under 2 months due to risk of neurological complications 3

Important Limitations

While mupirocin effectively reduces nasal colonization, it has not conclusively been shown to prevent infections in community settings. 2, 3 Long-term decolonization success is more likely in countries with low MRSA prevalence due to lower recolonization risk. 4 The decision to pursue decolonization should balance the treatment objective (short-term bacterial load reduction versus long-term eradication) against individual risk factors for treatment failure and the local epidemiology of MRSA. 4