How do I interpret Candida in the urine?

Dr Low Lee Lee
Infectious Disease Physician
Department of Medicine
Hospital Sultanah Bahiyah
Alor Setar, Malaysia

Candiduria in patients without an indwelling catheter

With a Candida-positive urine culture, clinicians must always differentiate colonization from infection. A clean-catch urine sample should be repeated for culture. If the second culture is sterile, no treatment is necessary. If the same Candida spp. is isolated from a symptomatic patient, it is considered significant; symptomatic and persistent candiduria indicates an infection. However, it remains a diagnostic challenge in critically ill or paraplegic patients. Under the circumstances of unexplained fever, candiduria may be considered significant in the critically ill. 

Presence of pyuria does not always indicate Candida urinary tract infections (UTI). In fact, a quarter of patients with funguria have concomitant bacteriuria.¹ Unlike bacterial UTI, in candiduria, quantitative urine cultures do not reliably predict infection.²

Managing candiduria in patients with an indwelling urinary catheter

Candida colonization of urinary tract is expected with prolonged catheterization. Studies have shown that candiduria may resolve if the urinary catheter is removed (35–40%) or replaced (20%).³ However, if candiduria persists and the patient remains febrile after removal or replacement of catheter, and there is no other obvious source of infection, antifungal treatment may be considered.

Does colonization predict invasive candidiasis?

With prolonged ICU stay, 80% of critically ill patients were found to be colonized with Candida spp.⁴ Nevertheless, only 1–8% of colonized patients develop candidemia.³ Colonization does not always culminate in infection, hence antifungal treatment is mostly not required. Empirical treatment may be needed in symptomatic patients with multiple sites of Candida colonizations and with significant risk factors for invasive candidiasis.³

References

1. Kauffman CA, et al. Clin Infect Dis 2000;30:14-18.
2. Bukhary ZA. Saudi J Kidney Dis Transpl 2008;19:350-360.
3. Alfouzan WA, Dhar R. J Mycol Med 2017;27:293-302.
4. Eggimann P, et al. J Hosp Infect 2015;89:302-308.