TABLE 6.
Guidelines for the management of infections due to community-associated methicillin-resistant Staphylococcus aureus (MRSA)
| Clinical disease | Key features | Management principles | Antimicrobial choices* |
|---|---|---|---|
| Skin and soft tissue infection (SSTI) | |||
|
| |||
| Mild | Localized disease Infected scratches Insect bites Furuncles Small abscesses Absence of systemic illness |
Culture selectively† No antibiotic therapy recommended except for young or immunocompromised host Cover draining lesions Emphasize personal hygiene Close follow-up Return if worsening |
Generally not indicated Topical antiseptic or antibacterial (eg, bacitracin) therapy may be considered. Systemic antimicrobial therapy may be considered in the young infant or immunocompromised host. |
| Moderate | Cellulitis Moderate abscesses Minimal or no associated systemic features |
Culture (blood if febrile, site if purulent) Drainage of abscess or needle aspiration Oral therapy in older child or adult Consider parenteral therapy for young or immunocompromised host Appropriate infection control measures Imaging for extent and complications (case by case) Close follow-up Return if worsening |
ET includes clindamycin 150 mg to 450 mg every 6 h po and ped dose of 30 mg/kg/day ÷ every 6 h to 8 h po, or TMP-SMX one double-strength tablet or two regular-strength tablets every 12 h po and ped dose of 8 mg/kg/day to 12 mg/kg/day (based on TMP component) ÷ every 12 h po/IV plus coverage for group A streptococcus, or doxycycline‡ 100 mg every 12 h po. If parenteral therapy is necessary, see choices for severe SSTI. Treat proven MRSA as above, based on sensitivity testing. If parenteral therapy is necessary, see choices for severe SSTI. |
| Severe | Extensive cellulitis Large or multiple abscesses Associated systemic features |
Culture (blood if febrile, site if purulent) Drainage of abscess Hospitalize Parenteral therapy Appropriate infection control measures Infectious disease consultation Imaging for extent and complications |
ET includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV. Some experts recommend adding cloxacillin or a first-generation cephalosporin while awaiting culture and sensitivity results (superior for MSSA). Clindamycin may be added in cases of toxin-mediated syndrome. Treatment for proven MRSA includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV. Alternatives include clindamycin 600 mg to 900 mg every 8 h IV/IM (if sensitive) and ped dose of 30 mg/kg/day to 40 mg/kg/day ÷ every 6 h to 8 h IV or TMP-SMX* 8 mg/kg/day to 10 mg/kg/day (based on TMP component) ÷ every 12 h IV (if sensitive) and ped dose of 8 mg/kg/day to 12 mg/kg/day (based on TMP component) ÷ every 6 h IV. Clindamycin is bacteriostatic and should not be used alone if a bactericidal drug is required. |
| Musculoskeletal infection (MSI) | |||
|
| |||
| Osteomyelitis | Preceding trauma Tendency for multifocal lesions Disease in adjacent muscle not uncommon Progression to chronic osteomyelitis possible May be complicated by DVT |
Cultures (blood, bone and tissue) Involve surgical team (early debridement and drainage) Infectious disease consultation Parenteral therapy Consider combination therapy for severe cases or if slow to respond Infection control measures Look for other infected sites (imaging) |
ET includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV, or clindamycin 600 mg to 900 mg every 8 h IV/IM/po and ped dose of 30 mg/kg/day to 40 mg/kg/day ÷ every 6 h to 8 h IV or po, or TMP-SMX 8 mg/kg/day to 10 mg/kg/day (based on TMP component) ÷ every 12 h IV and ped dose of 8 mg/kg/day to 12 mg/kg/day (based on TMP component) ÷ every 6 h IV. Treat proven MRSA as above, based on sensitivity testing. Addition of rifampin may be considered for osteomyelitis. |
| Pyomyositis | May be extensive Tendency for multifocal involvement |
Cultures (blood, tissue) Surgical drainage Infectious disease consultation Parenteral therapy Infection control measures Imaging |
Treat similiar to osteomyelitis. |
| Necrotizing fasciitis | Clinically indistinguishable from GAS disease Toxic High complication rate |
Cultures (blood and tissue) Surgical debridement Infectious disease consultation Parenteral therapy Infection control measures Imaging |
ET includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV. Some experts recommend adding cloxacillin or a first-generation cephalosporin while awaiting culture and sensitivity results (superior for MSSA). Clindamycin may be added in case of toxin-mediated syndrome. Adjuncts such as IVIG should be considered on a case-by-case basis in conjunction with ID specialist. Treat proven MRSA as above, based on sensitivity testing. |
| Respiratory tract infection (RTI) | |||
|
| |||
| Necrotizing pneumonia | Influenza-like prodrome, hemoptysis, fever, shock, leukopenia, pneumatoceles, abscesses, consolidation Respiratory failure High mortality |
Cultures (blood, pleural fluid and sputum) ID consultation Intensive care unit care Infection control measures Combination parenteral therapy Chest drainage if empyema |
ET includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV. Treat proven MRSA as above, based on sensitivity testing. Consider linezolid (superior for hospital-associated MRSA pneumonia [123,124]), as guided by ID opinion. |
| Other | |||
|
| |||
| Sepsis syndrome | Shock Multiorgan failure May have purpura fulminans Associated SSTI, MSI, RTI May be complicated by Waterhouse-Friedrichsen syndrome High mortality |
Blood cultures Culture any pus or fluid collection Look for primary or secondary focus ID consultation Intensive care unit care Imaging: look for occult abscesses, bone infection or endocarditis Involve surgery and other specialists as needed Infection control measures Parenteral, multidrug therapy Prolonged therapy for endovascular infections |
ET includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV. Some experts recommend adding cloxacillin or a first-generation cephalosporin while awaiting culture and sensitivity results (superior for MSSA). Clindamycin may be added in case of toxin-mediated syndrome. Adjuncts such as IVIG should be considered on a case-by-case basis in conjunction with ID specialist Proven MRSA treatment includes vancomycin 1 g every 12 h IV and ped dose of 40 mg/kg/day to 60 mg/kg/day ÷ every 6 h IV. Alternatives include clindamycin 600 mg to 900 mg every 8 h IV/IM (if sensitive) and a ped dose of 30 mg/kg/day to 40 mg/kg/day ÷ every 6 h to 8 h IV or TMP-SMX 8 mg/kg/day to 10 mg/kg/day (based on TMP component) ÷ every 12 h IV (if sensitive) and ped dose of 8 mg/kg/day to 12 mg/kg/day (based on TMP component) ÷ every 6h IV. Clindamycin is bacteriostatic and should not be used alone if a bactericidal drug is required. |
| Septic thrombophlebitis, DVT | Complicates musculoskeletal infection | Management as for sepsis syndrome, plus Doppler ultrasound, often found on magnetic resonance imaging Anticoagulation, under direction of hematology (159) |
Treat as above For endovascular infections, combination antimicrobial therapy is recommended (ie, vancomycin plus either gentamicin or rifampin) Prolonged therapy is required for endovascular infection, and expert advice from an ID specialist should be considered. |
| Endocarditis | Suspect if persistent bacteremia Pre-existing valvular heart disease may not be present |
Management as for sepsis syndrome, plus Echocardiogram Cardiology consultation ID consultation Parenteral therapy Monitor for complications (embolic phenomena and hemodynamic instability) |
|
*
Choice of antimicrobial therapy depends on local susceptibility patterns;
†
Patients with risk factors, as a part of an outbreak investigation, and patients with slowly responding or recurrent lesions;
‡
Not recommended for pediatric patients younger than eight years or during pregnancy. (AIII) Further information on antibiotic dosages and adverse effects can be found in Table 7. DVT Deep vein thrombosis; ET Empirical therapy; GAS Group A streptococcal; ID Infectious disease; IM Intramuscularly; IV Intravenously; IVIG Intravenous immunoglobulin; MSSA Methicillin-sensitive Staphylococcus aureus; ped Pediatric; po Orally; TMP-SMX Trimethoprim-sulfamethoxazole