Should asymptomatic bacteriuria be treated?

Asymptomatic Bacteriuria Treatment Guidelines

Asymptomatic bacteriuria should NOT be treated in most patient populations, with specific exceptions for pregnant women and patients undergoing urologic procedures with risk of mucosal bleeding. 1, 2

When to Screen and Treat

Treatment is recommended ONLY in the following populations:

1. Pregnant women 1, 2

   • Screen all pregnant women in first trimester
   • Treatment reduces risk of pyelonephritis (from 20-35% to 1-4%)
   • Treatment reduces incidence of low birth weight and preterm delivery

2. Patients undergoing urologic procedures with risk of mucosal bleeding 1, 2

   • Transurethral resection of prostate (TURP)
   • Other urological procedures where mucosal bleeding is anticipated
   • Treatment reduces risk of post-operative UTI

When NOT to Screen or Treat

Treatment is NOT recommended in the following populations:

• Premenopausal, non-pregnant women (A-I) 1
• Diabetic women (A-I) 1, 3
• Older persons living in the community (A-II) 1
• Elderly institutionalized patients (A-I) 1, 4
• Persons with spinal cord injury (A-II) 1, 2
• Catheterized patients while catheter remains in place (A-I) 1
• Patients with recurrent UTI (treatment may be harmful) 3
• Patients prior to joint replacement 3
• Renal transplant recipients (no definitive recommendation, C-III) 1

Diagnostic Criteria

Proper diagnosis is essential before considering treatment:

• Women: Two consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10^5 CFU/mL 1, 2
• Men: A single clean-catch voided urine specimen with one bacterial species isolated in a quantitative count ≥10^5 CFU/mL 1, 2
• Catheterized specimens: ≥10^2 CFU/mL 1, 2

Potential Harms of Unnecessary Treatment

Treating asymptomatic bacteriuria when not indicated can lead to:

• Development of antimicrobial resistance 2, 4
• Recurrence of bacteriuria with more resistant strains 2
• Adverse effects from antibiotics 2
• Increased risk of Clostridioides difficile infection 4
• Increased healthcare costs 4
• No improvement in clinical outcomes for most populations 4

Common Pitfalls to Avoid

1. Treating based on pyuria alone: Pyuria accompanying asymptomatic bacteriuria is NOT an indication for antimicrobial treatment (A-II) 1

2. Treating based on positive urine dipstick or microscopy: Urine culture is the gold standard for diagnosis 2

3. Treating elderly patients with nonspecific symptoms: Confusion, falls, or functional decline alone are not indications for treating bacteriuria 4

4. Treating catheterized patients: Nearly all long-term catheterized patients develop bacteriuria (100%), but treatment does not prevent symptomatic episodes 1

5. Treating post-menopausal women: Despite high prevalence (2.8-8.6%), treatment does not improve outcomes 1, 3

The evidence clearly shows that treating asymptomatic bacteriuria in most populations provides no benefit and may cause harm through antibiotic resistance and adverse effects. Following these guidelines promotes antimicrobial stewardship while ensuring appropriate treatment for the specific populations who benefit.