What is the management for a patient with a positive Methicillin-resistant Staphylococcus aureus (MRSA) nose swab?

Management of Positive MRSA Nasal Swab

For patients with a positive MRSA nasal swab but no active infection, decolonization therapy is recommended only if there is a history of recurrent skin infections or ongoing household transmission. 1

Assessment for Decolonization Therapy

• Routine decolonization is not recommended for all patients with positive MRSA nasal swabs 1
• Decolonization should be considered in the following scenarios:
  • Patient has recurrent MRSA skin and soft tissue infections despite optimizing wound care and hygiene measures 2, 1
  • Ongoing transmission is occurring among household members or other close contacts despite optimizing hygiene measures 2, 1
  • Patient is at high risk for surgical site infections (e.g., undergoing orthopedic or cardiac surgery) 3

Recommended Decolonization Protocol

• Nasal decolonization with mupirocin 2% ointment applied to both anterior nares twice daily for 5-10 days 2, 1
• Consider adding topical body decolonization with one of the following:
  • Chlorhexidine gluconate (CHG) body wash daily for 5-14 days 2, 1
  • Dilute bleach baths (1 teaspoon per gallon of water or ¼ cup per ¼ tub) for 15 minutes twice weekly for up to 3 months 2

Hygiene Measures for All MRSA Carriers

• Maintain good personal hygiene with regular bathing and hand cleaning with soap and water or alcohol-based hand sanitizer 2
• Keep draining wounds covered with clean, dry bandages 2
• Avoid sharing personal items that contact skin (e.g., razors, towels, bedding) 2
• Focus cleaning efforts on high-touch surfaces using commercially available cleaners 2

Monitoring and Follow-up

• Routine surveillance cultures following decolonization are not recommended in the absence of active infection 2, 1
• Screening cultures prior to decolonization are not routinely needed if at least one prior infection was documented as MRSA 2, 1

Special Considerations

Emerging Resistance to Mupirocin

• Recent studies show increasing mupirocin resistance, particularly among MRSA strains (up to 22.5% resistance) 3
• In high-risk patients (e.g., total joint replacement), alternative agents such as intranasal povidone-iodine may be preferable 3

Environmental Contamination

• Environmental surfaces in rooms of MRSA-colonized patients frequently become contaminated (>50% of surface samples may be positive) 4
• Enhanced environmental cleaning should be considered, particularly for patients with recurrent infections 4

Household Contact Management

• Evaluate symptomatic household contacts for possible MRSA infection 1
• Consider decolonization of household members if there is ongoing transmission within the household 1

Potential Pitfalls

• Decolonization may provide only temporary clearance, with recolonization occurring after discontinuation 1, 5
• Repeated use of mupirocin may lead to resistance development 3
• Failure to address environmental contamination may lead to recolonization 4

Remember that asymptomatic colonization alone does not require treatment unless there are specific risk factors for infection or transmission 1. The primary goal is to prevent progression to active infection and reduce transmission to others.