Management of Yeast and 3-10 RBCs in Urine
For a patient with yeast and 3-10 RBCs in urine, treatment depends entirely on whether symptoms are present—asymptomatic candiduria requires no treatment in most cases, while symptomatic patients should receive oral fluconazole 200 mg daily for 2 weeks. 1
Determining If Treatment Is Necessary
The critical first step is distinguishing colonization from infection, as most candiduria represents benign colonization that resolves without intervention 1:
- Asymptomatic patients without risk factors require only observation—no antifungal therapy is indicated 1, 2
- Remove predisposing factors first (indwelling catheters, unnecessary antibiotics), as this alone clears candiduria in approximately 50% of cases without antifungals 1, 2, 3
High-risk patients requiring treatment even when asymptomatic include: 1, 2, 4
- Neutropenic patients
- Patients undergoing urologic procedures or manipulation
- Severely immunocompromised patients with fever and candiduria
- Patients with urinary tract obstruction
- Infants with very low birth weight
The presence of 3-10 RBCs is nonspecific and does not by itself indicate infection—pyuria and hematuria cannot differentiate Candida colonization from true infection 1. Clinical symptoms (dysuria, frequency, urgency, flank pain, fever) are what determine the need for treatment 5, 6.
Treatment Algorithm for Symptomatic Patients
First-Line Therapy
For fluconazole-susceptible organisms (most commonly C. albicans): 1, 2
- Cystitis: Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1
- Pyelonephritis: Oral fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 1
Fluconazole is the drug of choice because it achieves high urinary concentrations in its active form and is available orally 1, 6, 3.
Alternative Therapy for Resistant Species
For fluconazole-resistant C. glabrata: 1, 5
- Amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily for 1-7 days (with or without flucytosine 25 mg/kg PO 4 times daily) 1
- Oral flucytosine 25 mg/kg 4 times daily for 7-10 days as monotherapy is an alternative 1
For C. krusei: 1
- Amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily for 1-7 days 1
Periprocedural Prophylaxis
For patients undergoing urologic procedures with candiduria: 1, 2, 4
Essential Non-Pharmacologic Interventions
These interventions are as important as antifungal therapy and should never be overlooked:
- Remove indwelling urinary catheters if feasible—this is a strong recommendation and often sufficient alone 1, 2
- Eliminate urinary tract obstruction—strongly recommended, as obstruction precludes successful antifungal treatment 1
- Remove or replace nephrostomy tubes/stents if present 1
Critical Pitfalls to Avoid
Do not use echinocandins or other azoles (voriconazole, posaconazole) for urinary Candida infections—these agents achieve minimal urinary concentrations and are ineffective for lower urinary tract infections 1, 2, 5, 3, 7. This is a common error that leads to treatment failure.
Do not use lipid formulations of amphotericin B—unlike amphotericin B deoxycholate, lipid formulations do not achieve adequate urine concentrations and have documented failures 1, 2, 5.
Do not treat asymptomatic candiduria in low-risk patients—this leads to unnecessary antifungal exposure, potential resistance development, and does not prevent candidemia 2, 4, 6. The exception is high-risk patients listed above.
Do not rely on colony counts or pyuria to diagnose infection—these parameters cannot differentiate colonization from infection, especially with indwelling catheters 1, 8. Clinical context and symptoms guide treatment decisions.
Duration and Monitoring
- Standard treatment duration is 2 weeks for both cystitis and pyelonephritis 1, 5
- Continue treatment until symptoms resolve and repeat urine cultures are negative for Candida 1
- Consider imaging (ultrasound or CT) if blood cultures remain positive to evaluate for metastatic complications, fungus balls, or structural abnormalities 1, 8