From the Guidelines
Significant fungal growth on a urine culture typically requires antifungal treatment, with fluconazole being the first-line therapy for most urinary fungal infections, as recommended by the Infectious Diseases Society of America in their 2016 clinical practice guideline 1.
Key Considerations
- The presence of yeast in the urine must be evaluated in the context of the particular clinical setting to determine its relevance and the need for antifungal therapy 1.
- For uncomplicated cases, fluconazole is the drug of choice, and treatment should be tailored based on the severity of the infection and the patient's underlying health status.
- The 2016 guideline by the Infectious Diseases Society of America suggests that fluconazole is effective in eradicating candiduria, especially in asymptomatic or minimally symptomatic patients 1.
Treatment Approach
- For uncomplicated cases, prescribe fluconazole 200mg orally on day 1, followed by 100mg daily for 7-14 days.
- For complicated infections or immunocompromised patients, extend treatment to 14-21 days.
- Alternative options include amphotericin B bladder irrigation for refractory cases or IV echinocandins for severe infections.
Underlying Risk Factors
- Fungal urinary tract infections often occur in patients with indwelling catheters, diabetes, recent antibiotic use, or immunosuppression.
- Treatment should include addressing underlying risk factors such as:
- Removing unnecessary catheters
- Optimizing blood glucose control
- Discontinuing unnecessary antibiotics
Follow-up and Monitoring
- Follow-up cultures are recommended after completing treatment to confirm eradication, especially in complicated cases.
- Asymptomatic candiduria in non-catheterized, non-immunocompromised patients may not require treatment as it often represents colonization rather than true infection 1.
From the Research
Implications of Significant Fungal Growth on a Urine Culture
- Significant fungal growth on a urine culture can be an indication of a fungal urinary tract infection (UTI), which can range from asymptomatic colonization to severe sepsis with fungemia 2.
- The presence of fungal species in urine can be due to hematogenous spread or retrograde infection via the urethra 3, 4.
- Major risk factors for fungal UTIs include diabetes mellitus, indwelling urinary catheters, use of broad-spectrum antibiotics, urinary obstruction, and admission to intensive care units 3, 2.
Clinical Features and Management
- Clinical features of fungal UTIs can vary from asymptomatic urinary tract colonization to cystitis, pyelonephritis, or severe sepsis with fungemia 2.
- Management of fungal UTIs depends on the patient's underlying health status and the presence of symptoms 3, 2.
- Treatment is recommended only when funguria is symptomatic or in cases of fungal colonization when host factors increase the risk of fungemia 3, 2.
- Antifungal agents used for funguria are mainly fluconazole and amphotericin B deoxycholate, as other drugs have extremely low concentrations in urine 3, 2, 5.
Diagnosis and Antifungal Susceptibility
- Microbiological diagnosis of funguria is usually based on a fungal concentration of more than 10^3/mm^3 in urine 2.
- Candida albicans is the most commonly isolated species, but previous antifungal treatment and previous hospitalization can affect both species and susceptibility to antifungal agents 2, 6.
- Antifungal susceptibility tests should be applied with identification of species for effective treatment 6.