What is the next step in managing a patient with a urine culture positive for Group B Streptococcus?

Management of Group B Streptococcus in Urine Culture

For a patient with Group B Streptococcus (GBS) isolated in urine culture, treatment with appropriate antibiotics is necessary regardless of colony count, and intrapartum antibiotic prophylaxis should be provided during labor if the patient is pregnant. 1

Assessment of Patient Status

First, determine if the patient is pregnant:

• If pregnant: Any amount of GBS in urine indicates heavy colonization and requires both immediate treatment of the current infection and intrapartum prophylaxis during labor 2, 1
• If non-pregnant: Treatment focuses on resolving the current urinary tract infection 1

Treatment Algorithm

For Pregnant Patients:

1. Immediate Treatment of Current UTI:

   • Treat with appropriate antibiotics for 7-10 days for uncomplicated UTI 1
   • Options include:
     • Penicillin or ampicillin (first-line therapy)
     • For penicillin-allergic patients: clindamycin (if susceptible) 1

2. Follow-up:

   • Obtain urine culture after completion of treatment to confirm eradication 1
   • No need to re-screen with vaginal-rectal cultures at 35-37 weeks as these women are presumed to be GBS colonized 3

3. Intrapartum Prophylaxis:

   • During labor, administer intravenous antibiotic prophylaxis: 2, 1

     • Penicillin G: 5 million units IV initially, then 2.5 million units IV every 4 hours until delivery, OR
     • Ampicillin: 2 g IV initially, then 1 g IV every 4 hours until delivery

   • For penicillin-allergic patients:

     • Low risk of anaphylaxis: Cefazolin 2 g IV initially, then 1 g IV every 8 hours
     • High risk of anaphylaxis: Clindamycin 900 mg IV every 8 hours (if susceptible) or Vancomycin 1 g IV every 12 hours (if resistant) 1

For Non-Pregnant Patients:

1. Treatment Options:

   • Treat for 7-10 days for uncomplicated UTI, 10-14 days for complicated UTI or pyelonephritis 1
   • Continue treatment for at least 48-72 hours after symptoms resolve 4
   • Options include:
     • Penicillin or ampicillin (first-line)
     • Nitrofurantoin for uncomplicated lower UTIs 1
     • For penicillin-allergic patients: cephalosporins (if no history of anaphylaxis) or clindamycin (if susceptible) 1

2. Follow-up:

   • Obtain urine culture after completion of treatment to confirm eradication

Important Considerations

• GBS in urine at any concentration indicates heavy colonization in pregnant women 2, 1
• Susceptibility testing is essential for penicillin-allergic patients due to increasing resistance to alternative antibiotics 1
• Erythromycin is not recommended due to increasing resistance 1
• Tetracyclines are contraindicated in pregnancy 1
• Fluoroquinolones should be avoided when alternatives exist 1

Pitfalls to Avoid

1. Failing to treat GBS bacteriuria in pregnancy: Any amount of GBS in urine during pregnancy requires treatment, regardless of colony count 2, 1, 3

2. Unnecessary re-screening: Women with GBS bacteriuria during pregnancy should not be re-screened with vaginal-rectal cultures at 35-37 weeks as they are presumed to be GBS colonized 3

3. Using oral antibiotics for intrapartum prophylaxis: Oral antibiotics alone are not adequate for GBS prophylaxis during labor 2

4. Inadequate follow-up: Failure to obtain a post-treatment urine culture to confirm eradication of the infection

5. Missing intrapartum prophylaxis: Women with GBS bacteriuria during the current pregnancy should receive intrapartum prophylaxis regardless of whether they received treatment earlier in pregnancy 2, 1

By following these guidelines, clinicians can effectively manage GBS urinary tract infections and reduce the risk of complications, including early-onset neonatal GBS disease in pregnant patients.