Treatment of Coagulase-Negative Staphylococcus (CoNS) Infections in Pediatric Patients
Initial Assessment: Determine if Treatment is Necessary
Do not initiate antibiotic treatment solely based on a positive blood culture for CoNS, as these organisms are common contaminants. 1
When to Treat CoNS in Pediatrics:
- Multiple positive blood cultures from different sites suggest true bacteremia rather than contamination 1
- Presence of indwelling central venous catheter or arterial line with clinical signs of infection 1
- Immunosuppressed patients (oncology, transplant, neutropenic) with positive cultures 1
- Clinical deterioration with fever, hemodynamic instability, or sepsis 1
- Prosthetic device infections (cardiac devices, shunts, prosthetic valves) 1
Primary Treatment Strategy
For Methicillin-Susceptible CoNS:
- First-line: Nafcillin or oxacillin 150-200 mg/kg/day IV divided every 6 hours 1
- Penicillin allergy: Cefazolin 100 mg/kg/day IV divided every 8 hours 2
For Methicillin-Resistant CoNS (MRCoNS):
Vancomycin is the primary treatment for serious CoNS infections in pediatric patients. 1
Vancomycin Dosing:
- Age 1-5 months: Start at 60 mg/kg/day IV divided every 6-8 hours 3
- Age 6 months-12 years: Start at 70 mg/kg/day IV divided every 6-8 hours 3
- Age 13-18 years: Start at 60 mg/kg/day IV divided every 6-8 hours 3
- Target trough levels: 10-20 mg/L for most infections 3
- Target AUC₂₄: ≥424 mg/L·h for bacteriological cure 4
Critical caveat: Standard empiric doses of 40-60 mg/kg/day achieve therapeutic levels in only 39% of pediatric patients, necessitating higher initial dosing and therapeutic drug monitoring 3
Alternative Agents for MRCoNS
Clindamycin (if susceptible and specific conditions met):
Use ONLY if:
Dosing: 10-13 mg/kg/dose IV every 6-8 hours (maximum 40 mg/kg/day) 1, 5
Transition to oral: 30-40 mg/kg/day divided into 3-4 doses if susceptible 5
Major pitfall: Clindamycin should NEVER be used for suspected or confirmed endocarditis or endovascular infections 5
Linezolid:
- Dosing:
- Consider for: Pneumonia, non-endovascular infections when vancomycin fails or is contraindicated 1
Device-Specific Management
Central Venous Catheter-Related CoNS Bacteremia:
If multiple blood cultures are positive for MRCoNS, remove the central and arterial lines (except during neonatal period). 1
Catheter Retention Criteria (attempt salvage only if ALL present):
- Patient is hemodynamically stable 1
- Coagulase-negative species (not S. aureus) 1
- No tunnel infection or port pocket infection 1
- Bacteremia clears within 48-72 hours of appropriate antibiotics 1
- No metastatic complications 1
Administer vancomycin through the infected line when attempting salvage to maximize local drug concentration 1
Mandatory catheter removal indications:
- Persistent bacteremia >72 hours despite appropriate antibiotics 1
- Tunnel or pocket infection 1
- Hemodynamic instability or septic shock 1
- Endocarditis or metastatic infection 1
- Candidemia (if co-infection) 1
Prosthetic Valve Endocarditis (PVE):
For MRCoNS PVE, use triple therapy: vancomycin + rifampin + gentamicin. 1
- Vancomycin: 15 mg/kg/dose IV every 6 hours for minimum 6 weeks 1
- Rifampin: 20 mg/kg/day divided every 12 hours for minimum 6 weeks 1
- Gentamicin: 3 mg/kg/day divided every 8 hours for first 2 weeks only 1
Important consideration: Some experts recommend delaying rifampin for several days to allow vancomycin penetration into vegetations and prevent rifampin resistance 1
Duration of Therapy
Uncomplicated Bacteremia (catheter-related, catheter removed):
- 7-14 days after catheter removal and blood culture clearance 1
Complicated Bacteremia (retained catheter, slow clearance):
- 14-21 days with close monitoring 1
Osteomyelitis:
- Minimum 8 weeks of therapy 1
Prosthetic Valve Endocarditis:
- Minimum 6 weeks of combination therapy 1
Pneumonia:
- 7-21 days depending on extent of infection and clinical response 1
Monitoring and Follow-up
Therapeutic Drug Monitoring:
- Vancomycin trough levels: Check before 4th dose, target 10-20 mg/L 3
- Consider AUC monitoring: Target AUC₂₄ ≥424 mg/L·h for serious infections 4
- Recheck levels: After any dose adjustment and weekly during prolonged therapy 3
Clinical Response Assessment:
- Repeat blood cultures 48-72 hours after initiating therapy to document clearance 1
- Daily clinical assessment for improvement in fever, hemodynamics, and inflammatory markers 1
- If no improvement by 72 hours: Consider catheter removal, alternative antibiotics, or occult metastatic foci 1
Echocardiography:
- Obtain echocardiogram if bacteremia persists >2-3 days or patient has prosthetic material 1
- Transthoracic echo (TTE) is adequate in young children due to thin chest wall 1
Special Populations
Neonatal Period:
- Do NOT routinely remove catheters in neonates with CoNS bacteremia unless specific indications present 1
- Vancomycin dosing requires age-specific adjustments and close monitoring 3
Immunocompromised/Neutropenic Patients:
- Initiate treatment even with single positive culture if clinically unstable 1
- Consider combination therapy with aminoglycoside for severe infections 1
- Do not delay treatment for culture confirmation in febrile neutropenia 1
Common Pitfalls to Avoid
Treating contamination: Not every positive CoNS culture requires treatment; assess clinical context and obtain repeat cultures 1
Inadequate vancomycin dosing: Standard 40-60 mg/kg/day doses are insufficient; start with 60-70 mg/kg/day based on age 3
Using clindamycin for endovascular infections: Clindamycin has no role in endocarditis or catheter-associated bacteremia with retained device 5
Failing to remove infected devices: Attempting medical management alone with retained infected catheters leads to treatment failure 1
Not monitoring for treatment failure: Repeat blood cultures at 48-72 hours are essential to document clearance 1
Ignoring local resistance patterns: Empiric therapy must account for institutional MRCoNS resistance rates 1
Premature discontinuation: CoNS infections require adequate duration based on infection site and complications 1