Urinary Tract Infections Due to Candida albicans

Infection of the urinary tract due to Candida albicans is an uncommon but well-described complication of modern therapeutics. Despite the rarity of this infection, culture of properly collected urine yielding C. albicans requires an explanation. The significance of systemic factors in the defense of the urinary tract against candidal infection is unknown, but secretions from the prostate gland in men and from periurethral glands in women have been reported to be fungistatic. In addition, growth of Candida at sites on mucous membranes may be suppressed by other normal flora. Conditions that predispose to candiduria include diabetes mellitus, antibiotic and corticosteroid therapy, as well as factors such as local physiology and disturbance of urine flow. Lower urinary tract candidiasis is usually the result of a retrograde infection, while renal parenchymal infection most often follows candidemia. In addition to asymptomatic candiduria, recognized clinical forms of candidal urinary tract infections include bladder infection, renal parenchymal infection, and infections associated with fungus ball formation. Unfortunately, clinical criteria alone are insufficient to distinguish reliably among these clinical types. If the urine is found to contain candidal organisms, the condition of the patient should be considered for determination of appropriate therapy. When infection is thought to be confined to the bladder, patients without indwelling bladder catheters should be considered for flucytosine therapy. For patients requiring indwelling bladder catheterization, irrigation with amphotericin B is usually successful. Although flucytosine alone may be useful for renal parenchymal candidal infection, iv amphotericin B alone or the combination of amphotericin B and flucytosine is indicated when systemic candidiasis cannot be excluded.