What are the implications and treatment options for a 2-year-old child with moderate yeast cells in their urine, potentially indicating a fungal urinary tract infection (UTI)?

Management of Moderate Yeast Cells in Urine of a 2-Year-Old

In a 2-year-old with moderate yeast cells in urine, treatment is indicated ONLY if the child is symptomatic (fever, dysuria, irritability) or has specific high-risk factors (neutropenia, upcoming urologic procedure), as asymptomatic candiduria represents colonization in most cases and does not require antifungal therapy. 1, 2

Initial Assessment and Risk Stratification

Determine if treatment is necessary by evaluating:

• Clinical symptoms: Fever, dysuria, crying on urination, irritability, feeding difficulties, or systemic signs 3, 4
• High-risk factors requiring treatment even if asymptomatic:
  • Neutropenia or immunocompromised state 1, 2
  • Planned urologic procedure 1, 2
  • Very low birth weight (if applicable) 2
• Presence of indwelling urinary catheter: Remove if present, as this alone resolves candiduria in approximately 50% of cases 5, 6

Most children with yeast in urine are simply colonized and do not have true infection. 5, 6, 2

When NOT to Treat

Do not initiate antifungal therapy if:

• Child is asymptomatic (no fever, no urinary symptoms, feeding well, acting normally) 1, 5, 2
• No high-risk factors present 1, 2
• Asymptomatic candiduria does not require treatment in otherwise healthy children 1, 5, 6, 2

Treatment Algorithm for Symptomatic Fungal UTI

If treatment is indicated based on symptoms or risk factors:

First-Line Therapy: Oral Fluconazole

• Fluconazole is the antifungal agent of choice because it achieves high urinary concentrations with oral administration 1, 7, 5, 6, 2
• Dosing for pediatric patients: 6 mg/kg on day 1, then 3 mg/kg daily 7
• Duration: 7-14 days for urinary tract infections 1, 7
• Advantages: Oral formulation, excellent urine penetration, well-tolerated 5, 2

Alternative Therapy: Amphotericin B Deoxycholate

• Reserved for fluconazole-resistant organisms (C. glabrata, C. krusei), fluconazole allergy, or treatment failure 1, 2
• Requires intravenous administration 1
• Achieves adequate urine concentrations even at low doses 1
• Major drawback: Need for IV access and potential toxicity 1

Agents to AVOID

Do NOT use the following for fungal UTI in children:

• Echinocandins (caspofungin, micafungin, anidulafungin): Do not achieve adequate urine concentrations 1, 5
• Other azoles (voriconazole, posaconazole, isavuconazole): Minimal urinary excretion 1
• Lipid formulations of amphotericin B: Do not achieve adequate urine levels 1

Diagnostic Confirmation

Before initiating treatment, obtain:

• Urine culture via catheterization or suprapubic aspiration (NOT bag collection) 3, 8
• Colony count threshold: ≥50,000 CFU/mL of Candida species from catheterized specimen confirms infection 8
• Urinalysis for pyuria: UTI diagnosis requires BOTH yeast on culture AND pyuria (≥5 WBC/HPF) 3, 8
• Species identification and susceptibility testing: Essential for guiding therapy, especially to identify fluconazole-resistant species 1, 6, 2

Addressing Predisposing Factors

Critical steps to prevent recurrence:

• Remove indwelling urinary catheter if present - this alone resolves candiduria in ~50% of cases 5, 6
• Discontinue broad-spectrum antibiotics if possible 6, 2
• Optimize diabetes control if applicable 6, 2
• Evaluate for urinary obstruction or anatomic abnormalities 3, 2

Follow-Up Strategy

• Clinical reassessment within 48-72 hours to confirm symptom resolution 3
• Repeat urine culture is NOT routinely necessary if symptoms resolve 5, 6
• If fever persists beyond 48 hours of appropriate therapy: Consider imaging (renal ultrasound) to evaluate for fungus ball, obstruction, or pyelonephritis 1, 3

Critical Pitfalls to Avoid

• Do not treat asymptomatic candiduria - this is colonization, not infection, and treatment promotes antifungal resistance 1, 5, 6, 2
• Do not use echinocandins or non-fluconazole azoles for urinary candidiasis - they do not achieve therapeutic urine levels 1, 5
• Do not rely on bag-collected urine specimens for culture - false-positive rate is unacceptably high 3
• Do not assume all yeast species are fluconazole-susceptible - C. glabrata and C. krusei may be resistant 1, 6, 2

Special Considerations for C. glabrata or C. krusei

If fluconazole-resistant species identified:

• Amphotericin B deoxycholate IV is the treatment of choice 1, 2
• Bladder irrigation with amphotericin B (50 mg in 1000 mL sterile water) may be considered for cystitis, though recurrence is common 1
• Endoscopic evaluation may be needed if obstructing lesions suspected 1