What is the recommended management and antibiotic treatment for asymptomatic bacteriuria in pregnant women and patients undergoing urologic or gynecologic procedures that may cause mucosal bleeding?

Management of Asymptomatic Bacteriuria

Screen for and treat asymptomatic bacteriuria in only two clinical scenarios: pregnant women and patients undergoing urologic procedures that breach the mucosa with anticipated mucosal bleeding. 1

When to Screen and Treat

Pregnant Women

• Screen all pregnant women at least once in early pregnancy (ideally at 12-16 weeks gestation or first prenatal visit) with urine culture 1, 2, 3
• Treat if culture shows ≥10⁵ CFU/mL on two consecutive specimens 2, 3
• Use a short-course regimen of 3-7 days with targeted antibiotics based on culture results 1, 2, 3
• Single-dose fosfomycin trometamol is an acceptable alternative 1
• Perform periodic screening for recurrent bacteriuria following treatment 2, 3
• The rationale is prevention of pyelonephritis, low birth weight, and preterm delivery 3, 4

Urologic Procedures with Mucosal Bleeding

• Screen before any endoscopic urologic procedure that breaches the mucosa (transurethral resection of prostate, bladder tumor resection, ureteroscopy with lithotripsy, percutaneous stone surgery) 1
• Obtain urine culture before the procedure to guide targeted antimicrobial therapy rather than empiric treatment 1
• Initiate antimicrobial therapy 30-60 minutes before the procedure 1, 2
• Use a short course of 1-2 doses only 1
• Discontinue antibiotics immediately after the procedure unless an indwelling catheter remains in place 1
• If a catheter remains post-procedure, continue antibiotics until catheter removal 1, 2
• The risk of bacteremia is up to 60% and sepsis 6-10% in untreated bacteriuric patients undergoing these procedures 1, 2

Gynecologic Procedures

• The evidence does not specifically address gynecologic procedures with mucosal bleeding 1
• By extrapolation from urologic data, screening and treatment would be reasonable for gynecologic procedures with anticipated significant mucosal trauma 1

When NOT to Screen or Treat

Do not screen or treat asymptomatic bacteriuria in the following populations, as treatment causes harm without benefit: 1, 5, 2

• Nonpregnant women of any age (including premenopausal and postmenopausal) 1, 5, 2
• Patients with well-controlled diabetes mellitus (both men and women) 1, 5, 2, 3
• Elderly patients (community-dwelling or institutionalized in long-term care) 1, 5, 2, 3
• Patients with indwelling urinary catheters while the catheter remains in place (100% develop bacteriuria due to biofilm formation) 5, 2, 3
• Patients with spinal cord injury 1, 5, 2
• Renal transplant recipients (beyond 1 month post-transplant) 1, 5
• Patients with recurrent UTIs (treatment is actually harmful in this group) 1, 4
• Patients with dysfunctional or reconstructed lower urinary tract 1
• Patients before orthopedic arthroplasty surgery 1
• Patients before cardiovascular surgeries 1

Special Consideration: Post-Catheter Removal

• For women with catheter-acquired bacteriuria persisting 48 hours after catheter removal, treatment may be considered (weak recommendation) 1, 2
• A 3-day regimen may be sufficient for women ≤65 years without upper tract symptoms 2
• Insufficient data exist for men in this scenario 2

Critical Pitfalls to Avoid

The Pyuria Trap

• The presence of pyuria with asymptomatic bacteriuria is NOT an indication for treatment 1, 5, 2, 3
• Pyuria without symptoms does not distinguish asymptomatic bacteriuria from symptomatic UTI 5
• Do not order urine cultures in asymptomatic patients, as positive results promote unnecessary antibiotic use 2

Harms of Unnecessary Treatment

• Treatment increases antimicrobial resistance 5, 2, 4
• Five times more days of antibiotic exposure with significantly more adverse drug events 2, 3
• Higher risk of reinfection with resistant organisms 2, 3
• Increased risk of Clostridioides difficile infection 3
• No reduction in symptomatic UTI, mortality, or morbidity in non-indicated populations 2, 4

Common Misinterpretations in Elderly Patients

• Cloudy or smelly urine alone should not be interpreted as symptomatic infection 3
• Confusion, falls, or functional decline may represent true UTI requiring focal genitourinary symptoms for diagnosis 3
• Dipstick testing has poor specificity and should not trigger treatment 3

Diagnostic Criteria for Asymptomatic Bacteriuria

• Women: Two consecutive voided urine specimens with the same bacterial strain ≥10⁵ CFU/mL 2, 3
• Men: Single clean-catch voided specimen with ≥10⁵ CFU/mL 1, 2, 3
• Catheterized patients: Single specimen with ≥10² CFU/mL 2, 3
• Essential requirement: Complete absence of urinary tract symptoms (dysuria, frequency, urgency, suprapubic pain) 3