What is the recommended management for streptococcal (Streptococcus) infections in infants?

Management of Streptococcal Infections in Infants

The management of streptococcal infections in infants requires prompt identification and appropriate antibiotic therapy based on the type of infection, with penicillin, ampicillin, or amoxicillin as first-line treatments for most streptococcal infections.

Group B Streptococcus (GBS) Management

Early-Onset GBS Disease Prevention

• Maternal intrapartum antibiotic prophylaxis (IAP) is the primary prevention strategy for early-onset GBS disease 1
• Indications for maternal IAP include:
  • GBS culture-positive within preceding 5 weeks
  • GBS status unknown with risk factors (< 37 weeks' gestation, rupture of membranes ≥ 18 hours, temperature ≥ 100.4°F/38.0°C)
  • GBS bacteriuria during current pregnancy
  • History of a previous infant with GBS disease 1

Recommended IAP Regimens

• Preferred: Penicillin G or ampicillin IV for ≥ 4 hours before delivery
• For penicillin-allergic women at low risk of anaphylaxis: Cefazolin
• For penicillin-allergic women at high risk of anaphylaxis: Clindamycin (only if GBS isolate is confirmed susceptible) or vancomycin 1

Management of Newborns Based on Risk Factors

1. Infants with signs of sepsis:

   • Full diagnostic evaluation (including lumbar puncture)
   • Immediate empirical antimicrobial therapy 1

2. Well-appearing infants born to mothers with chorioamnionitis:

   • Limited evaluation (blood culture, CBC with differential and platelets)
   • Empirical antimicrobial therapy 1, 2

3. Well-appearing infants whose mothers received adequate IAP:

   • Routine care and observation for 48 hours
   • May be discharged after 24 hours if term birth and ready access to medical care 1

4. Well-appearing term infants with inadequate/no maternal IAP:

   • If rupture of membranes < 18 hours: Observation for 48 hours
   • If rupture of membranes ≥ 18 hours: Limited evaluation and observation for 48 hours 1

5. Preterm infants (< 37 weeks) with inadequate/no maternal IAP:

   • Limited evaluation and observation for 48 hours 1

6. Preterm infants < 35 weeks with high-risk conditions:

   • Blood culture and empiric antibiotics regardless of maternal IAP status
   • Consider lumbar puncture if high suspicion for GBS disease 1

Antibiotic Treatment Regimens

For Neonates with Suspected GBS Disease

• First 7 days of life: Ampicillin plus aminoglycoside 1, 2
• 8-28 days of age: Ampicillin plus ceftazidime (without meningitis)
• 29-90 days of age: Ceftriaxone 1
• Add vancomycin if meningitis is suspected or for critically ill patients 1

For Group A Streptococcus (GAS) Infections

Pharyngitis/Tonsillitis

• First-line: Penicillin V or amoxicillin
  • Amoxicillin: 50-75 mg/kg/day in 2 doses 1, 3
  • Penicillin V: 50-75 mg/kg/day in 3-4 doses 1
• Duration: Minimum 10 days to prevent acute rheumatic fever 3, 4
• For penicillin allergy: Oral clindamycin (30-40 mg/kg/day in 3-4 doses) 1

Invasive GAS Infections

• Parenteral therapy: Penicillin (100,000-250,000 U/kg/day) or ampicillin (200 mg/kg/day) 1
• Alternatives: Ceftriaxone, cefotaxime, or clindamycin (if susceptible) 1

Special Considerations

Dosing in Young Infants

• For infants < 12 weeks (3 months): Maximum dose of amoxicillin is 30 mg/kg/day divided every 12 hours due to immature renal function 3
• Treatment should continue for at least 48-72 hours beyond resolution of symptoms 3

Antibiotic Resistance Concerns

• Increasing resistance to macrolides (erythromycin) and clindamycin among GBS isolates 1, 5
• Clindamycin should never be used for GBS without susceptibility testing 1
• Some GBS isolates have shown reduced susceptibility to penicillin, though it remains first-line therapy 5

Compliance Factors for Outpatient Treatment

• Consider palatability, cost, duration, and frequency when selecting oral antibiotics for infants 6
• Once or twice daily dosing improves compliance compared to more frequent dosing 6

Common Pitfalls to Avoid

1. Failure to obtain appropriate cultures before starting antibiotics in suspected invasive disease
2. Inadequate duration of therapy for GAS pharyngitis (minimum 10 days required)
3. Using clindamycin without susceptibility testing for GBS infections
4. Stopping antibiotics too early based on clinical improvement alone
5. Not recognizing signs of late-onset GBS disease (typically presents as bacteremia, meningitis, or focal infections between 7-90 days of life) 1
6. Inappropriate antibiotic selection for penicillin-allergic patients

By following these evidence-based guidelines, clinicians can effectively manage streptococcal infections in infants while minimizing morbidity and mortality.