Funguria and Fungal Urinary Tract Infection (UTI)

Background

• Funguria refers to the presence of fungi in the urine.
• Candiduria refers to the presence of Candida species in the urine, the most common form of funguria.
• The vast majority of cases are asymptomatic and represent colonization rather than infection.
• Rarely, the presence of yeast in the urine is a sign of disseminated infection.
• Infection most often involves the lower urinary tract.
• Urinary catheterization is a major risk factor.
• Immunosuppression and use of broad-spectrum antibacterial agents are also risk factors.
• Candida spp. are the most commonly identified pathogens.
• If present, signs and symptoms vary with the site of infection.
  • Dysuria, frequency, urgency, and hematuria are symptoms of cystitis.
  • Fever, flank pain, and rigors are symptoms of pyelonephritis.
  • Urinary retention, hesitancy, hematuria, and flank pain may be symptoms of fungus balls.
  • Systemic inflammatory response may be seen with renal candidiasis or concurrent fungemia.

Evaluation

• Distinguishing infection from colonization is often challenging.
• No diagnostic criteria have been established and decision to treat is based on clinical context:
  • > 10,000-15,000 colony-forming units (CFU)/mcL suggests infection in patients without catheters, but is not diagnostic
  • urinary colony counts are not meaningful in catheterized patients
• Pyuria does not distinguish colonization from infection.
• Decision to treat is typically based on presence of compatible symptoms not attributable to other causes.

Management

• Treatment is not recommended for asymptomatic patients except for high-risk patients such as neonates and those with neutropenia or having urologic procedures (Strong recommendation).
• Fluconazole is preferred first-line agent in adults when treatment is needed and isolate is susceptible (Strong recommendation):
  • for cystitis, fluconazole 200 mg orally (3 mg/kg) daily for 14 days
  • for pyelonephritis, fluconazole 200-400 mg orally (3-6 mg/kg) daily for 14 days
  • for fungus balls:
    • surgical removal plus
    • fluconazole 200-400 mg orally (3-6 mg/kg) daily until symptoms resolve and urine culture are negative
• Amphotericin deoxycholate is the recommended alternative for fluconazole-resistant isolates.
• For treatment of fungal prostatitis and/or epididymo-orchitis, consider amphotericin or fluconazole, and the possible requirement for incision and drainage of any accompanying abscess.