What are the guidelines for diagnosis and treatment (Tx) of urinary tract infections (UTIs) in Australia?

Australian Guidelines for Diagnosis and Treatment of Urinary Tract Infections

For diagnosis and treatment of urinary tract infections in Australia, antibiotics should only be prescribed for symptomatic UTIs, with first-line options including trimethoprim, cephalexin, or amoxicillin with clavulanate based on local sensitivity patterns. 1

Diagnosis of UTI

Clinical Diagnosis

• UTI diagnosis requires both symptoms and bacteriuria
• Symptoms indicating UTI:
  • New onset dysuria
  • Urinary frequency
  • Urgency to urinate
  • Nocturia
  • Suprapubic discomfort 2

Laboratory Diagnosis

• Urine microscopy, culture and sensitivity (M/C/S) should be sent in patients with symptoms potentially indicating UTI 1
• Routine dipstick testing is not recommended as it has poor predictive value 1
• Significant bacteriuria defined as:
  • ≥50,000 CFUs/mL of a single uropathogen in appropriately collected specimen 1
  • Pure growth of 250,000 CFUs/mL of a uropathogen with urinalysis showing bacteriuria or pyuria 1

Important Diagnostic Considerations

• In catheterized patients:
  • Indwelling catheters should be changed prior to urine collection 1
  • Pyuria is common and has no predictive value in differentiating symptomatic UTI from asymptomatic bacteriuria 1
• Asymptomatic bacteriuria:
  • Should NOT be treated in most populations 2
  • Urine odor, cloudiness, and/or pyuria alone are not sufficient to indicate infection 1

Treatment Approach

Empiric Antibiotic Therapy

• The majority of uncomplicated UTIs in Australia can be treated with:

  • Trimethoprim
  • Cephalexin
  • Amoxicillin with clavulanate 1

• Treatment duration:

  • 7-14 days for most UTIs 1, 2

• Empiric therapy should be started based on:

  • Suspected causative organisms' antibiotic sensitivities
  • Then adjusted based on urine culture results 1

Special Populations

Spinal Cord Injured Patients

• Antibiotic therapy only indicated for symptomatic UTI 1
• Asymptomatic bacteriuria should not be treated 1
• Consider specialist review for UTI in patients with:
  • Medical comorbidities (e.g., single kidney)
  • Recent travel to regions with high antibiotic resistance (e.g., Southeast Asia) 1

Pediatric Patients

• Diagnosis based on presence of pyuria and at least 50,000 CFUs/mL of a single pathogen 1
• Treatment duration: 7-14 days 1
• After UTI treatment, parents should be instructed to seek prompt medical evaluation (within 48 hours) for future febrile illnesses 1

Antibiotic Selection Based on Patient Factors

Renal Impairment

• Dose adjustment required based on creatinine clearance:
  • For example, with fluoroquinolones:
    • CrCl ≥50 mL/min: standard dose
    • CrCl 30-50 mL/min: reduced dose
    • CrCl 5-29 mL/min: further reduced dose 2, 3

Complicated UTIs

• Ciprofloxacin recommended for pyelonephritis if local resistance patterns allow 2
• For severe/complicated UTIs: consider parenteral therapy initially until clinical improvement 3

Prevention of Recurrent UTIs

Non-Antimicrobial Strategies

• Increasing fluid intake strongly recommended 2
• Vaginal estrogen replacement for postmenopausal women 2
• Avoid practices that disrupt normal vaginal flora 2

Antimicrobial Prophylaxis

• Options include:
  • Trimethoprim-sulfamethoxazole
  • Nitrofurantoin
  • Cephalexin
  • Fosfomycin 2, 4

Common Pitfalls to Avoid

1. Treating asymptomatic bacteriuria - This creates antimicrobial resistance without clinical benefit 1, 2

2. Relying on dipstick testing alone - Not recommended as it has poor predictive value 1

3. Failing to collect urine culture before starting antibiotics - Urine should be tested prior to initiation of antibiotics 1

4. Not adjusting therapy based on culture results - Antibiotic choice should be re-evaluated once urine M/C/S results are available 1

5. Unnecessary post-treatment testing - No routine post-treatment urinalysis or cultures are indicated for asymptomatic patients 2

6. Overuse of fluoroquinolones - Should be reserved for pyelonephritis, complicated UTIs, or patients with documented history of resistant pathogens 2

The management of UTIs requires a balanced approach to ensure effective treatment while practicing antimicrobial stewardship. Following these evidence-based guidelines will help reduce inappropriate antibiotic use and combat increasing antimicrobial resistance in Australia.