What is the recommended treatment for a 24-year-old female patient with a Group B streptococcal (GBS) urinary tract infection (UTI), considering the potential for pregnancy?

Treatment of Group B Streptococcus UTI in a 24-Year-Old

Treat this GBS UTI with penicillin or ampicillin for 7-10 days, and if the patient is or could be pregnant, she must also receive intrapartum IV antibiotic prophylaxis during labor regardless of whether you treat the UTI now. 1, 2

Critical First Step: Determine Pregnancy Status

• Pregnancy status fundamentally changes management because GBS bacteriuria in pregnancy mandates both immediate treatment AND intrapartum prophylaxis during labor, while non-pregnant patients only need treatment if symptomatic 1, 3
• In a 24-year-old woman of reproductive age, obtain a pregnancy test immediately before prescribing antibiotics 2
• The CDC guidelines emphasize that any concentration of GBS in urine during pregnancy indicates heavy genital tract colonization and significantly increases risk of early-onset neonatal GBS disease 4, 2

If Patient is NOT Pregnant

Treatment Approach

• Penicillin G 500 mg orally every 6-8 hours for 7-10 days is the preferred agent due to narrow spectrum activity 1
• Ampicillin 500 mg orally every 8 hours for 7-10 days is an acceptable alternative 1
• For penicillin-allergic patients, use clindamycin 300-450 mg orally every 8 hours with susceptibility testing performed before use due to increasing resistance (3-15% of GBS isolates) 1, 5

Key Caveat for Non-Pregnant Patients

• Only treat if the patient is symptomatic (dysuria, frequency, urgency, suprapubic pain) or has underlying urinary tract abnormalities 1
• If the patient has GBS in urine but is completely asymptomatic with normal urinalysis, this represents asymptomatic bacteriuria that should NOT be treated according to 2019 IDSA guidelines 1
• Treating asymptomatic bacteriuria leads to unnecessary antibiotic exposure, resistance development, and potential adverse effects without clinical benefit 1

Follow-Up

• Follow-up urine culture after treatment completion may be warranted to ensure eradication, especially in patients with recurrent UTIs 1

If Patient IS Pregnant

Immediate Treatment of UTI

• Treat the acute UTI immediately according to standard pregnancy UTI protocols using pregnancy-safe antibiotics 4, 2
• Penicillin or ampicillin are first-line agents and safe in pregnancy 2, 5
• Nitrofurantoin is also appropriate for GBS UTI in pregnancy according to antibiotic sensitivity patterns 5
• Complete the full prescribed course to ensure eradication 2

Critical: Intrapartum Prophylaxis is MANDATORY

• All pregnant women with GBS bacteriuria at ANY concentration during ANY trimester must receive IV antibiotic prophylaxis during labor, regardless of whether the UTI was treated earlier in pregnancy 4, 3, 2
• This is because treating the UTI does NOT eliminate GBS colonization from the genitourinary tract—recolonization after oral antibiotics is typical 2
• Women with GBS bacteriuria are heavily colonized and at increased risk of delivering an infant with early-onset GBS disease 4, 3

Intrapartum Prophylaxis Regimens

For patients without penicillin allergy:

• Penicillin G 5 million units IV initially, then 2.5 million units IV every 4 hours until delivery (preferred) 2
• Ampicillin 2 g IV initially, then 1 g IV every 4 hours until delivery (acceptable alternative) 2

For penicillin-allergic patients (not high-risk for anaphylaxis):

• Cefazolin 2 g IV initially, then 1 g IV every 8 hours until delivery 2

For penicillin-allergic patients at high risk for anaphylaxis:

• Clindamycin 900 mg IV every 8 hours until delivery (if isolate confirmed susceptible) 2
• Vancomycin 1 g IV every 12 hours until delivery (if isolate resistant to clindamycin or susceptibility unknown) 2

Timing and Efficacy

• Intrapartum prophylaxis must be administered ≥4 hours before delivery for maximum effectiveness 2
• When given ≥4 hours before delivery, prophylaxis is 78% effective in preventing early-onset neonatal GBS disease 2

Important Documentation

• Women with documented GBS bacteriuria at any point in pregnancy should NOT be re-screened with vaginal-rectal cultures at 35-37 weeks 2
• They are presumed to be GBS colonized and automatically qualify for intrapartum prophylaxis 2
• Ensure laboratory reports of GBS bacteriuria are communicated to both the anticipated site of delivery and the ordering provider 2

Common Pitfalls to Avoid

• Do NOT assume treating the UTI eliminates the need for intrapartum prophylaxis in pregnancy—this is a common and dangerous error 2
• Do NOT treat asymptomatic bacteriuria in non-pregnant patients—this leads to unnecessary antibiotic exposure and resistance without benefit 1
• Do NOT use oral or IV antibiotics before labor to treat GBS colonization in pregnancy—this is completely ineffective at eliminating colonization and should never be done 3, 2
• For penicillin-allergic pregnant patients at high risk for anaphylaxis, susceptibility testing for clindamycin must be performed due to 3-15% resistance rates 2, 5
• Resistance to clindamycin, azithromycin, and ceftriaxone is relatively high (19-31% in some studies), so antibiotic sensitivities should guide treatment in penicillin-allergic patients 5