Can a patient contract another Methicillin-resistant Staphylococcus aureus (MRSA) infection after decolonization and how is effective decolonization achieved?

MRSA Recolonization After Decolonization: Risk and Effective Strategies

Yes, patients can contract another MRSA infection after decolonization, with recurrence rates of approximately 35% even after successful initial decolonization. 1 Effective decolonization requires a comprehensive protocol targeting multiple colonization sites simultaneously, with nasal mupirocin and chlorhexidine body washes being the cornerstone interventions.

Risk of MRSA Recolonization

MRSA recolonization can occur due to several factors:

• Incomplete initial decolonization
• Persistent environmental contamination
• Colonized household contacts
• Respiratory tract colonization (increases failure risk by 9.1 times) 1
• Specific MRSA strains (spa-type 002 has 5.8 times higher recolonization risk) 1
• Most recurrences (88%) occur within 270 days after decolonization 1

Effective Decolonization Protocol

The Infectious Diseases Society of America (IDSA) recommends decolonization in two specific scenarios 2:

1. When a patient develops recurrent MRSA skin and soft tissue infections (SSTI) despite optimizing wound care and hygiene measures
2. When ongoing transmission is occurring among household members or close contacts despite optimizing wound care and hygiene measures

Recommended Decolonization Regimen:

• Nasal decolonization: Mupirocin ointment applied to nares twice daily for 5-10 days 2
• Body decolonization: Chlorhexidine body wash for 5-14 days 2
• Alternative body decolonization: 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

Recent research shows this combined approach reduces MRSA infection risk by 30% compared to education alone, with fully adherent patients experiencing 44% fewer MRSA infections 3.

Monitoring After Decolonization

• Surveillance cultures following decolonization are not routinely recommended in the absence of active infection 2
• Screening cultures prior to decolonization are not routinely recommended if at least one prior infection was documented as MRSA 2
• A follow-up period of approximately 12 months after decolonization is reasonable to monitor for recurrence 1

Additional Measures to Prevent Recolonization

Environmental Hygiene:

• Focus cleaning on high-touch surfaces (counters, doorknobs, bathtubs, toilet seats) 2
• Use commercially available cleaners according to label instructions 2
• Avoid sharing personal items (razors, linens, towels) 2

Household Contact Management:

• Evaluate contacts for evidence of MRSA infection 2
• Treat symptomatic contacts 2
• Consider decolonization of asymptomatic household contacts 2

Common Pitfalls to Avoid

1. Incomplete decolonization: Failure to address all colonization sites simultaneously reduces effectiveness 4
2. Overuse of mupirocin: Can lead to resistance development; only use when MRSA colonization is confirmed 5
3. Neglecting environmental contamination: High-touch surfaces can serve as reservoirs for recolonization 2
4. Ignoring household contacts: Family members can be asymptomatic carriers and recolonize successfully decolonized patients 2
5. Inadequate follow-up: Most recurrences occur within 9 months, requiring appropriate monitoring period 1

Special Considerations

• Respiratory tract colonization significantly increases decolonization failure risk and may require additional interventions 1
• Oral antibiotics for decolonization should only be considered when all other decolonization attempts and environmental controls have been exhausted 5
• The nares are a central hub for MRSA colonization, making nasal mupirocin the most crucial component of decolonization therapy 4

By implementing this comprehensive approach to MRSA decolonization and prevention of recolonization, healthcare providers can significantly reduce the risk of recurrent MRSA infections in their patients.