Outpatient crystalluria: prevalence, crystal types, and associations with comorbidities and urinary tract infections at a provincial hospital.

Background and objectives: Crystalluria refers to the occurrence of crystals in urine resulting from urinary supersaturation, which disrupts the balance between factors that promote and those that inhibit crystal formation in urine. This study aimed to assess the prevalence of crystalluria, identify crystal types, determine associated comorbidities, and assess links with bacterial urinary tract infections in outpatients at Hassan II Hospital in Settat.

Materials and methods: A retrospective study was conducted from January 2022 to May 2023 at Hassan II Hospital. Urine samples from patients suspected of urinary tract infections, who underwent cytobacteriological urine examinations, were analyzed.

Results: Among 1,025 urine samples, 22.04% showed crystalluria. The mean age of patients was 51.3 with a standard deviation of 18.1 years. The most common crystal types were calcium oxalate (46.4%), uric acid (23.5%), urates (15.1%) and struvite (9.3%). Comorbidities including, diabetes, kidney failure, prostatitis, and nephrotic syndrome was associated with urinary crystal formation. The prevalence of urinary tract infections in patients with urinary crystals was 10.6%. Struvite crystals were specifically associated with bacterial infections, especially with Proteus mirabilis, Escherichia coli, Citrobacter freundii, Citrobacter koseri, and Enterobacter cloacae.

Conclusion: Monitoring urinary crystals is essential for preventing the formation of kidney calculi and crystal-associated infections, especially in high-risk individuals.