Does a home‑acquired MRSA skin/soft‑tissue infection have a higher recurrence rate than a postoperative MRSA surgical‑site infection, warranting decolonization?

Home-Acquired MRSA Skin Infections Have Higher Recurrence Rates Than Postoperative MRSA Surgical Site Infections

Home-acquired MRSA skin and soft tissue infections carry substantially higher recurrence risk (up to 65% with environmental contamination) compared to postoperative MRSA surgical site infections, which primarily result from transient perioperative contamination rather than persistent colonization. 1, 2

Key Distinction in Infection Pathophysiology

The fundamental difference lies in the source and persistence of bacterial exposure:

• Postoperative MRSA SSIs arise from transient perioperative contamination during the surgical procedure itself, not from ongoing endogenous colonization 1
• Home-acquired MRSA SSTIs result from persistent environmental contamination and ongoing colonization of household members and surfaces 2, 3
• Clean elective surgeries have lower baseline infection rates, with MRSA typically originating from exogenous environmental sources during the procedure rather than persistent carriage 1

Recurrence Risk Data

Home-Acquired MRSA Infections

• 65% recurrence rate when household environmental contamination is present with concordant MRSA strains 2
• 35.5% recurrence rate even without detectable environmental contamination 2
• Environmental contamination doubles the rate of recurrent infection (incident rate ratio 2.05) 2
• Among children with community-associated MRSA SSTI, 53% of index patients and 19% of household contacts experienced recurrent infections within 12 months 3
• Persistent MRSA colonization increases recurrence risk by 56% (OR 1.56) 3

Postoperative MRSA SSIs

• No specific recurrence data provided in guidelines, as these infections are considered distinct events related to individual surgical procedures 1
• Standard perioperative prophylaxis is sufficient; extended postoperative prophylaxis is not recommended 1

Management Approach Based on Infection Source

For Home-Acquired MRSA SSTIs (High Recurrence Risk)

Decolonization is warranted when:

• Patients experience 3-4 MRSA SSTI episodes per year despite addressing predisposing factors 1
• Household environmental contamination is documented 2, 3

Recommended decolonization protocol:

• Intranasal mupirocin 2% ointment twice daily for 5 days 4
• Combined with daily chlorhexidine body washes or dilute bleach baths (1 teaspoon per gallon, 15 minutes, twice weekly for 3 months) 4
• Mupirocin reduces persistent colonization risk by 56% (OR 0.44) 3

Prophylactic antibiotics for frequent recurrences:

• Oral penicillin or erythromycin twice daily for 4-52 weeks 1
• Alternatively, intramuscular benzathine penicillin every 2-4 weeks 1
• Continue as long as underlying risk factors remain uncontrolled 1

Address underlying predisposing factors aggressively:

• Lymphedema, venous insufficiency, skin breakdown, obesity, eczema, and interdigital toe-web abnormalities 1, 5
• Failure to control these conditions markedly increases recurrence risk 1

Environmental decontamination:

• Household environmental contamination is present in 24% of homes after MRSA infection 2
• Increasing environmental contamination pressure increases persistent colonization (OR 1.17 per unit increase) 3
• Environmental decontamination should be considered, particularly where infection has occurred 2

For Postoperative MRSA SSIs (Lower Recurrence Risk)

Standard perioperative prophylaxis only:

• Tailor antibiotic prophylaxis to the specific surgical procedure 1
• No extended postoperative prophylaxis beyond standard perioperative regimen 1
• Most postoperative MRSA SSIs arise from perioperative factors, not persistent colonization 1

Focus on intraoperative infection control:

• Proper surgical technique and sterile procedures 1
• Appropriate perioperative antibiotic selection based on procedure type 6

Critical Pitfalls to Avoid

• Do not apply postoperative SSI management principles to home-acquired MRSA SSTIs - they are fundamentally different entities with different recurrence mechanisms 1
• Do not initiate decolonization for a single postoperative MRSA SSI - this represents transient contamination, not persistent colonization 1
• Do not neglect household contacts and environmental surfaces in home-acquired MRSA - 39% of household members become persistently colonized, often with the same strain 3
• Do not use decolonization as monotherapy - it must be combined with aggressive management of predisposing conditions 1, 5
• Complete the full 5-day mupirocin course even if symptoms improve, as incomplete treatment may contribute to resistance 4