What are the diagnostic and treatment approaches for patients with recurrent Urinary Tract Infections (UTIs)?

Diagnostic Approach for Recurrent UTI

For patients with recurrent UTI (≥3 UTIs/year or ≥2 UTIs in 6 months), obtain a urine culture with antimicrobial susceptibility testing for each symptomatic episode before initiating treatment. 1

Essential Laboratory Testing

• Urine culture is mandatory for diagnosis of recurrent UTI with a strong recommendation from the 2024 European Association of Urology guidelines 1
• Obtain urinalysis and culture prior to initiating antibiotics with each acute symptomatic episode 1
• A positive culture with >10² colony-forming units/mL in symptomatic patients confirms the diagnosis 2
• If initial specimen is suspect for contamination, obtain a catheterized specimen 1

What NOT to Do

• Do not perform routine cystoscopy or full abdominal ultrasound in women younger than 40 years with recurrent UTI and no risk factors (weak recommendation) 1
• Do not obtain surveillance urine testing or cultures in asymptomatic patients between UTI episodes 1
• Do not treat asymptomatic bacteriuria in non-pregnant patients with recurrent UTI, as this fosters antimicrobial resistance and increases recurrence 1

When to Pursue Additional Workup

Consider imaging and cystoscopy only when:

• Women ≥40 years old with recurrent UTI 1
• Risk factors for complicated UTI are present (structural/functional urinary tract abnormalities, immunosuppression, pregnancy) 1
• Repeated pyelonephritis occurs (suggests complicated etiology) 1
• History of urolithiasis, renal function disturbances, or high urine pH 1

Risk Factor Assessment

Postmenopausal women - evaluate for:

• Atrophic vaginitis due to estrogen deficiency 1
• Urinary incontinence 1
• Cystocele and high post-void residual urine volume 1

Premenopausal women - assess for:

• Frequency of sexual intercourse (strongest predictor of recurrence) 2
• Use of spermicides 1

Treatment of Acute Episodes

First-Line Antibiotic Therapy

Use nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin as first-line agents dependent on local antibiogram 1:

• Nitrofurantoin: 100 mg twice daily for 5 days 1
• Fosfomycin trometamol: 3 g single dose (women only) 1, 3
• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days (women) or 7 days (men) 1, 4

Treatment Duration

• Treat for ≤7 days for acute cystitis episodes in recurrent UTI patients 1
• Use the shortest effective duration to minimize antimicrobial resistance 1
• For treatment failures, assume the organism is not susceptible to the original agent and retreat with a 7-day regimen using another agent 1

Patient-Initiated Treatment

Self-start antibiotic therapy can be offered to select reliable patients who will obtain urine specimens before starting therapy and communicate effectively with their provider 1

Prevention Strategies - Algorithmic Approach

Step 1: Non-Antimicrobial Interventions (Try First)

Postmenopausal women:

• Vaginal estrogen replacement (strong recommendation) 1
• Consider adding lactobacillus-containing probiotics 1

Premenopausal women:

• Increase fluid intake (weak recommendation) 1
• Behavioral modifications: avoid spermicides, harsh cleansers, control blood glucose in diabetics 1

All patients:

• Immunoactive prophylaxis (strong recommendation for all age groups) 1
• Methenamine hippurate for women without urinary tract abnormalities (strong recommendation) 1
• Cranberry products (weak recommendation, low quality evidence with contradictory findings) 1
• D-mannose (weak recommendation, weak and contradictory evidence) 1
• Probiotics with proven efficacy strains (weak recommendation) 1

Step 2: Antimicrobial Prophylaxis (When Non-Antimicrobial Fails)

Premenopausal women with post-coital infections:

• Low-dose post-coital antibiotics within 2 hours of sexual activity for 6-12 months 1

Premenopausal women with infections unrelated to sexual activity:

• Daily low-dose antibiotic prophylaxis 1

Preferred prophylactic agents:

• Nitrofurantoin 50 mg daily 1
• Trimethoprim-sulfamethoxazole 40/200 mg daily 1
• Trimethoprim 100 mg daily 1

Avoid fluoroquinolones and cephalosporins for prophylaxis due to collateral damage and resistance concerns 1

Step 3: Advanced Interventions

Endovesical instillations of hyaluronic acid or hyaluronic acid plus chondroitin sulfate for patients who have failed less invasive approaches (weak recommendation, further studies needed) 1

Critical Pitfalls to Avoid

• Never classify recurrent UTI patients as "complicated" unless they have structural/functional urinary tract abnormalities, immunosuppression, or pregnancy - this leads to unnecessary broad-spectrum antibiotics 1
• Avoid fluoroquinolones for empiric treatment due to increased resistance rates and collateral damage 1, 5
• Do not use daily antibiotic prophylaxis in patients managing bladders with clean intermittent catheterization or indwelling catheters who do not have recurrent UTI 1
• Nitrofurantoin is preferred for re-treatment since resistance is low and decays quickly if present 1

Antimicrobial Stewardship Considerations

• Base antibiotic selection on prior culture data and local antibiograms 1
• Consider rotating antibiotics at 3-month intervals to avoid selection of antimicrobial resistance 1
• Choose agents with least impact on normal vaginal and fecal flora 1
• Daily antibiotic prophylaxis is most effective (reducing UTI rate to 0.4/year) but most expensive; symptomatic self-treatment offers best cost per quality-adjusted life-year 6