When is treatment of group B strep (GBS) in urine recommended?

Treatment of Group B Streptococcus in Urine

When to Treat GBS in Urine

Group B Streptococcus (GBS) in urine should be treated at any concentration during pregnancy, and in non-pregnant adults when colony counts reach 10,000-49,000 CFU/mL or higher, as this represents significant bacteriuria requiring treatment. 1

Pregnant Women

GBS bacteriuria during pregnancy requires two distinct management approaches:

1. Immediate treatment of acute UTI if symptomatic:

   • Standard duration of therapy: 7-14 days 1
   • First-line antibiotics: Penicillin, ampicillin, or amoxicillin 1
   • Alternatives for penicillin allergy: Cefazolin, clindamycin, or vancomycin based on sensitivity testing 1

2. Intrapartum antibiotic prophylaxis (IAP) during labor:

   • Required regardless of whether treatment was given earlier in pregnancy 2, 1
   • Women with GBS bacteriuria do not need additional GBS screening at 36-37 weeks 2, 3

Intrapartum Antibiotic Prophylaxis Regimens:

• Penicillin G: 5 million units IV initial dose, then 2.5-3.0 million units IV every 4 hours until delivery 1
• Ampicillin: 2 g IV initial dose, then 1 g IV every 4 hours until delivery 1
• For penicillin allergy: Cefazolin 2 g IV initial dose, then 1 g IV every 8 hours until delivery 1

Important caveat: Antibiotics given during pregnancy do not eliminate GBS from the genitourinary and gastrointestinal tracts; recolonization after treatment is typical 1

Non-Pregnant Adults

Treatment is indicated in the following scenarios:

• GBS bacteriuria at concentrations of 10,000-49,000 CFU/mL or higher 1
• Any concentration if the patient has urinary symptoms
• Any concentration in patients with urinary tract abnormalities or who are immunocompromised 1

Clinical Considerations

Pregnancy-Specific Considerations

• GBS bacteriuria at any concentration during pregnancy is a recognized risk factor for early-onset GBS disease in newborns 1
• The CDC and ACOG guidelines clearly state that GBS isolated from urine in any concentration during pregnancy requires both treatment and subsequent intrapartum prophylaxis 2, 3
• Untreated GBS bacteriuria in pregnancy is associated with higher rates of preterm labor and premature rupture of membranes 4
• Patients with GBS-positive status who have preterm and prelabor rupture of membranes after 34 weeks are not candidates for expectant management due to higher rates of neonatal infectious complications 5

Non-Pregnancy Considerations

• In non-pregnant adults, GBS bacteriuria may signal underlying urinary tract abnormalities that warrant evaluation 1
• For GBS bacteremia, standard duration of therapy is 10-14 days, but extended therapy (4+ weeks) may be necessary if evidence of endocarditis or metastatic infection is present 1
• Follow-up cultures should be obtained to document clearance of bacteremia, as persistent bacteremia beyond 4 days has been associated with increased mortality 1

Pitfalls to Avoid

1. Not treating GBS bacteriuria in pregnancy regardless of colony count

   • Even low colony counts are significant during pregnancy 2, 1

2. Failing to provide intrapartum prophylaxis

   • Women with GBS bacteriuria during pregnancy need IAP during labor even if they received treatment earlier 2, 1

3. Missing communication between providers

   • Information about GBS bacteriuria should be communicated to all providers involved in the patient's care, particularly those who will manage labor and delivery 1

4. Overlooking recolonization

   • Treatment during pregnancy does not eliminate the risk of recolonization 1

5. Ignoring GBS in non-pregnant adults with risk factors

   • Consider treatment in patients with urinary tract abnormalities or immunocompromise even with lower colony counts 1