Management of Urinary Tract Infection with >100,000 CFU/mL of Yeast

Initial Clinical Decision: Treat or Observe?

Most patients with candiduria >100,000 CFU/mL do not require antifungal treatment unless they are symptomatic, neutropenic, very low-birth-weight infants (<1500g), or undergoing urologic procedures, as recommended by the Infectious Diseases Society of America 1
Neutropenic patients require treatment, according to the Infectious Diseases Society of America 1
Very low-birth-weight infants (<1500g) require treatment, as stated by the Infectious Diseases Society of America 1
Patients scheduled for urologic procedures within several days require treatment, as recommended by the Infectious Diseases Society of America 1
Patients with fever and candiduria who are severely immunocompromised (concern for disseminated candidiasis) require treatment, according to the Infectious Diseases Society of America 2

Oral fluconazole 200 mg (3 mg/kg) daily for 14 days is the first-line treatment for fluconazole-susceptible Candida species, as recommended by the Infectious Diseases Society of America 1, 2, 3
Amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily for 1-7 days is an alternative regimen for fluconazole-resistant organisms, according to the Infectious Diseases Society of America 1, 3
Oral flucytosine 25 mg/kg four times daily for 7-10 days is an alternative regimen for fluconazole-resistant organisms, as stated by the Infectious Diseases Society of America 1, 3
Amphotericin B bladder irrigation (50 mg/L sterile water) may be considered for refractory C. glabrata or C. krusei cystitis, though relapse rates are high (>80-90%), as noted by the Infectious Diseases Society of America 2, 4

Surgical or endoscopic removal is mandatory in adults with fungus balls (bezoars), combined with antifungal therapy, as recommended by the Infectious Diseases Society of America 4
If candiduria occurs with fever in a severely immunocompromised patient, treat as candidemia with echinocandin therapy (not fluconazole), according to the Infectious Diseases Society of America 2, 3

Do not treat asymptomatic candiduria in non-high-risk patients, as this leads to unnecessary antifungal exposure and potential resistance, as stated by the Infectious Diseases Society of America 1
Never use echinocandins or non-fluconazole azoles for Candida UTI, as they do not achieve therapeutic urinary concentrations, according to the Infectious Diseases Society of America 4
Always remove catheters before or during treatment, as failure to address this predisposing factor leads to treatment failure and relapse, as recommended by the Infectious Diseases Society of America 2
Bladder irrigation with amphotericin B has >80% relapse rates, reserve this only for refractory fluconazole-resistant cystitis when systemic therapy has failed, as noted by the Infectious Diseases Society of America 2, 4

The Infectious Diseases Society of America recommends fluconazole as the drug of choice for treating Candida urinary tract infections, with a recommended dosage of 200 mg (3 mg/kg) daily for 2 weeks for fluconazole-susceptible organisms 5, 6, 7

For fluconazole-susceptible organisms, the American College of Clinical Pharmacology recommends oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 7
For fluconazole-resistant C. glabrata, the Infectious Diseases Society of America recommends amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days OR oral flucytosine 25 mg/kg 4 times daily for 7-10 days 7, 8
For C. krusei, the American College of Clinical Pharmacology recommends amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 7

Fluconazole is preferred due to its high concentrations in urine, oral formulation, and proven effectiveness in a randomized, double-blind, placebo-controlled trial for candiduria 5
Flucytosine has good activity against many Candida species, but has toxicity concerns and risk of resistance development when used alone 5, 6

The Infectious Diseases Society of America recommends treatment for patients undergoing urologic procedures, with oral fluconazole 400 mg (6 mg/kg) daily OR amphotericin B deoxycholate 0.3-0.6 mg/kg daily for several days before and after the procedure 9
For patients with nephrostomy tubes or stents, consideration should be given to removal or replacement if feasible 7

Colony count in urine cannot reliably differentiate between colonization and infection, especially when a catheter is present 6, 7
Echinocandins may be effective for renal parenchymal infections despite poor urinary concentrations, but clinical data is limited 5
Bladder irrigation with amphotericin B resolves candiduria in 80-90% of patients but has high recurrence rates and is generally discouraged except for specific cases 5