Utility of Urine KOH in Detecting Candiduria in Infants

Background: Candida species are common cause of urinary tract infection in infants requiring medical care. Candida fungal elements may be demonstrated in urine using microscopic examination with potassium hydroxide (KOH). However, detection of these elements does not always correlate with candiduria. Objectives: To establish the utility of urine KOH in identifying candiduria and to determine the risk factors, as well as urinalysis and CBC parameters associated with candiduria. Methods: This prospective cross-sectional study included admitted infants 1 year and below with urine culture and with any risk factor/s for candiduria. Additional urine KOH testing was done using clean catch or catheter method. Urine culture was used as the gold standard. Results: Among the 90 study participants with both urine culture and urine KOH, 13 (14%) had candiduria. The use of indwelling catheter, presence of urinary tract anomalies, positive leukocyte esterase in urinalysis, and increased monocyte counts in CBC are all associated with candiduria. Urine KOH has sensitivity of 100%, (CI 75.2-100%), specificity 59.7%, (CI 47.9-70.7%), PPV 29.5%, (CI 17.7-45.2%), and NPV 100%, (CI 92.2-100%) in detecting candiduria. Conclusions: Negative urine KOH has excellent negative predictive value, while positive urine KOH result may warrant further investigation. Urine KOH results should be interpreted with caution depending on patient’s risk factors, clinical status, and other laboratory results prior to initiation of empiric antifungal therapy. Positive urine KOH may not always require treatment.