What is the recommended management for asymptomatic bacteriuria, such as Group B Streptococcus (GBS), in a clean catch urine sample from a non-pregnant woman without symptoms or risk factors for complications?

Management of Asymptomatic Bacteriuria in Non-Pregnant Women

Asymptomatic bacteriuria (ASB) in a non-pregnant woman without risk factors should NOT be treated with antibiotics, as treatment provides no benefit and may cause harm. 1, 2

Definition and Diagnosis

• ASB is defined as the presence of significant bacteria in urine without urinary symptoms
• Diagnostic criteria for ASB in women: two consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10^5 CFU/mL 1
• A clean catch urine sample showing Group B Streptococcus (GBS) or other bacteria without symptoms represents ASB

Evidence-Based Management Approach

For Non-Pregnant Women Without Risk Factors:

• Do not screen for ASB in asymptomatic non-pregnant women 1
• Do not treat ASB when incidentally discovered 1, 2
• Do not perform surveillance urine cultures in asymptomatic patients with history of recurrent UTIs 1

Rationale for Non-Treatment:

1. No clinical benefit: Multiple high-quality studies show no improvement in:

   • Rates of symptomatic UTI development
   • Renal function
   • Hypertension
   • Mortality 1

2. Potential harms of treatment:

   • Development of antimicrobial resistance
   • Elimination of protective bacterial strains
   • Adverse drug effects
   • Increased risk of C. difficile infection
   • Higher costs 1, 2

3. Evidence of potential harm: Some evidence suggests that treating long-term stable ASB may actually increase the risk of symptomatic UTI development 1, 2

Special Considerations

When to Screen and Treat ASB:

1. Pregnant women - Screen in early pregnancy and treat if positive 1, 2
2. Patients undergoing urologic procedures with anticipated mucosal bleeding 1
3. Patients prior to transurethral resection of the prostate 1

Populations Where ASB Should NOT Be Treated:

• Premenopausal, non-pregnant women 1
• Postmenopausal women 1
• Diabetic women 1
• Elderly persons (institutionalized or community-dwelling) 1
• Persons with spinal cord injury 1
• Catheterized patients while catheter remains in place 1

Common Pitfalls to Avoid

1. Misinterpreting pyuria: The presence of pyuria (≥10 WBCs/high-power field) with ASB is not an indication for treatment 1, 2
2. Overtreatment: Treating ASB can disrupt protective bacterial flora and lead to colonization with more resistant organisms 1, 2
3. Unnecessary urine cultures: Avoid surveillance cultures in asymptomatic patients 1
4. Attributing non-specific symptoms to bacteriuria in elderly patients 2

Key Takeaway

For a non-pregnant woman with Group B Streptococcus or other bacteria in a clean catch urine sample without symptoms, the evidence-based approach is clear: do not treat with antibiotics. Treatment provides no clinical benefit and may cause harm through antibiotic resistance, adverse effects, and disruption of protective bacterial flora.