What is the initial workup and treatment for a patient with yeast in their urine, specifically a urinary tract infection (UTI) caused by Candida?

Workup and Treatment of Yeast in Urine

For asymptomatic candiduria, no treatment is recommended except in high-risk patients (neutropenic patients, very low birth weight infants, and patients undergoing urologic procedures). 1

Initial Workup

• Determine if candiduria represents colonization, contamination, or true infection:

  • Assess for symptoms (dysuria, frequency, urgency, suprapubic pain)
  • Evaluate risk factors: diabetes mellitus, indwelling catheters, broad-spectrum antibiotics, urinary obstruction, ICU admission 2
  • Determine if patient belongs to high-risk category requiring treatment regardless of symptoms

• Laboratory evaluation:

  • Urine culture with species identification and susceptibility testing
  • Complete blood count to assess for systemic infection
  • Blood cultures if systemic infection is suspected

Management Algorithm

1. Asymptomatic Candiduria

• For most patients: No antifungal treatment required 1

• Remove predisposing factors when possible:

  • Remove or replace indwelling catheters
  • Discontinue unnecessary antibiotics
  • Correct urologic abnormalities

• Exceptions requiring treatment despite absence of symptoms:

  • Neutropenic patients
  • Very low birth weight infants
  • Patients undergoing urologic procedures

2. Symptomatic Candida Cystitis

• First-line treatment: Fluconazole 200 mg (3 mg/kg) daily for 2 weeks 3, 1
• For fluconazole-resistant species (e.g., C. glabrata):
  • Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days, OR
  • Flucytosine 25 mg/kg 4 times daily for 7-10 days 3, 1

3. Candida Pyelonephritis

• First-line treatment: Fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 3
• For fluconazole-resistant strains:
  • Amphotericin B deoxycholate 0.5-0.7 mg/kg daily with or without flucytosine 25 mg/kg 4 times daily for 2 weeks 3

4. Fungus Balls

• Surgical intervention is strongly recommended 3, 1
• Antifungal therapy:
  • Fluconazole 200-400 mg (3-6 mg/kg) daily, OR
  • Amphotericin B deoxycholate 0.5-0.7 mg/kg daily with or without flucytosine 3
• If access to renal collecting system is available, consider irrigation with amphotericin B deoxycholate (50 mg/L sterile water) 3

Important Considerations

• Duration of treatment: Continue until symptoms resolve and urine cultures are negative 1

• Follow-up: Obtain follow-up urine cultures to document clearance 1

• Medication considerations:

  • Echinocandins (caspofungin, micafungin, anidulafungin) have minimal urinary excretion and are generally ineffective for UTIs 1
  • Voriconazole and other azoles (except fluconazole) have poor urinary concentrations 1
  • Fluconazole achieves high urinary levels and is the preferred agent 2, 4

• Pitfalls to avoid:

  • Failing to identify Candida species (C. glabrata and C. krusei may be fluconazole-resistant) 1
  • Inadequate duration of treatment leading to recurrence 1
  • Treating asymptomatic candiduria in patients without risk factors 2, 4
  • Using antifungals with poor urinary excretion (echinocandins, most azoles except fluconazole) 4

Remember that in most hospitalized patients, especially those in ICUs, candiduria represents colonization rather than infection, and antifungal therapy is not required 5. However, candiduria can be a sign of disseminated infection, particularly in critically ill newborns 5.