Do I need to refer a patient with Methicillin-resistant Staphylococcus aureus (MRSA) infection to an infectious disease specialist or can I treat it myself?

Management of MRSA Infections: When to Refer to Infectious Disease

Most MRSA infections can be effectively managed by primary care providers without infectious disease specialist referral, particularly for uncomplicated skin and soft tissue infections. 1

Assessment of MRSA Infection Severity

Uncomplicated MRSA Infections (Can Be Managed by Primary Care)

• Localized skin and soft tissue infections (SSTIs)
• Absence of systemic symptoms
• No evidence of deep tissue involvement
• Immunocompetent host
• No treatment failures with appropriate therapy

Complicated MRSA Infections (Consider ID Referral)

• Bacteremia/bloodstream infections
• Endocarditis
• Osteomyelitis/septic arthritis
• Pneumonia
• Prosthetic device infections
• Treatment failures despite appropriate therapy
• Immunocompromised patients
• Recurrent infections

Treatment Approach for MRSA Infections

Uncomplicated Skin and Soft Tissue Infections

1. Incision and drainage is the primary treatment for abscesses

2. Oral antibiotic options:

   • Trimethoprim-sulfamethoxazole (TMP-SMX): 1-2 DS tablets twice daily
   • Doxycycline: 100 mg twice daily
   • Clindamycin: 300-450 mg three times daily (if local resistance <10%)
   • Linezolid: 600 mg twice daily (for severe infections)

3. Duration: 5-10 days for most uncomplicated SSTIs 1

Complicated MRSA Infections (Requiring ID Consultation)

1. MRSA Bacteremia/Endocarditis:

   • Vancomycin IV (15 mg/kg every 12 hours) OR
   • Daptomycin IV (6 mg/kg/day, FDA-approved for MRSA bacteremia) 2
   • Duration: At least 2 weeks for uncomplicated bacteremia, 4-6 weeks for complicated bacteremia or endocarditis 1, 2

2. Deep-seated infections (osteomyelitis, prosthetic joint infections):

   • Require surgical consultation for debridement/drainage
   • Prolonged antibiotic therapy (4-6 weeks)
   • ID consultation strongly recommended

Prevention of Recurrent MRSA Infections

1. Personal hygiene measures:

   • Regular bathing with soap and water
   • Hand hygiene with soap or alcohol-based sanitizers
   • Avoid sharing personal items (razors, towels, etc.)

2. Environmental measures:

   • Clean high-touch surfaces with detergent
   • Launder clothing and bedding in hot water

3. Decolonization (for recurrent infections):

   • Nasal mupirocin twice daily for 5-10 days
   • Chlorhexidine body washes for 5-14 days 1

When to Definitely Refer to Infectious Disease

1. MRSA bacteremia - All cases should be referred due to:

   • High mortality (15-25%)
   • Need for appropriate duration determination
   • Evaluation for metastatic foci of infection
   • Monitoring for treatment response 3

2. Treatment failures - Patients who fail initial appropriate therapy

3. Complicated infections:

   • Endocarditis
   • Central nervous system infections
   • Osteomyelitis/septic arthritis
   • Prosthetic device infections

4. Severe drug allergies limiting treatment options

5. Recurrent MRSA infections despite appropriate treatment and decolonization

Pitfalls to Avoid

1. Inadequate source control - Failure to drain abscesses or remove infected devices

2. Inappropriate antibiotic selection - Using antibiotics with poor MRSA activity

3. Insufficient treatment duration - Especially for deep-seated infections

4. Missing endocarditis - Always consider echocardiography in MRSA bacteremia 1

5. Overlooking metastatic foci - MRSA can seed to distant sites from primary infection

6. Failure to obtain appropriate cultures before starting antibiotics in suspected serious infections 1

In summary, while many MRSA infections can be managed by primary care providers, complicated infections, bacteremia, and treatment failures warrant infectious disease consultation to optimize outcomes and reduce mortality.