Treatment of Symptomatic Group B Streptococcus Bacteriuria

Diagnostic Considerations

The American Academy of Pediatrics and other guideline societies recommend that symptomatic patients with 10,000-25,000 CFU/mL of Group B Streptococcus (GBS) in urine culture should be treated according to current standards of care for urinary tract infection 1
Lower CFU counts can indicate significant infections in symptomatic patients, and the historical 100,000 CFU/mL threshold is increasingly recognized as too rigid 2
For catheterized specimens, the diagnostic threshold is ≥50,000 CFU/mL, but this must be interpreted with clinical symptoms and urinalysis results 3

The Centers for Disease Control and Prevention recommends treating symptomatic patients according to standard UTI protocols when the patient has urinary symptoms (dysuria, urgency, frequency) plus evidence of pyuria and/or bacteriuria on urinalysis 1
The presence of symptoms combined with positive urinalysis (leukocyte esterase, nitrites, WBCs, or bacteria on microscopy) supports treatment 2
Women with symptomatic or asymptomatic GBS urinary tract infection detected during pregnancy should be treated according to current standards 1
Prenatal culture-based screening at 35-37 weeks is not necessary for women with documented GBS bacteriuria 1, 5

If the patient is truly asymptomatic (no urinary symptoms), treatment should not be initiated 6, 7
Treating asymptomatic bacteriuria may be harmful and contributes to antimicrobial resistance, adverse drug effects, and C. difficile infection 6
Laboratories should report GBS in urine when present at concentrations ≥10⁴ CFU/mL (10,000 CFU/mL) in pure culture or mixed with a second microorganism 5
Specimens from collection bags cannot be used for definitive diagnosis and require confirmation 3, 4