Association Between Microscopic Urinalysis Findings and Urine Culture Results Among Female Patients with Suspected Urinary Tract Infection.

Abstract

Microscopic urinalysis is widely used as a rapid preliminary test in patients with suspected urinary tract infection (UTI), although its findings do not always correspond with urine culture results. This retrospective cross-sectional study assessed the association between microscopic urinalysis findings and laboratory-reported urine culture outcomes among female patients investigated for suspected UTI at Duhok Obstetrics and Gynecology Teaching Hospital, Duhok, Iraq.  Laboratory records generated between February and June 2023 were reviewed, and 47 records with corresponding microscopic urinalysis and urine culture results were included. The evaluated findings were pyuria, microscopic hematuria, increased epithelial-cell counts, and microscopic bacteriuria. Associations with culture growth were assessed using Fisher’s exact test, with odds ratios (ORs) and 95% confidence intervals (CIs). Culture growth was detected in 11 specimens (23.4%), including eight monomicrobial cultures (17.0%) and three polymicrobial cultures (6.4%), whereas 36 specimens (76.6%) showed no growth. Fourteen bacterial isolates were recovered; Escherichia coli was the most frequent (35.7%), followed by Klebsiella spp. (28.6%). Pyuria (OR = 7.07; 95% CI: 1.33–37.65; P = 0.017) and microscopic bacteriuria (OR = 20.00; 95% CI: 2.29–175.05; P = 0.001) were significantly associated with culture growth. The combined presence of pyuria and microscopic bacteriuria showed 81.8% sensitivity, 77.8% specificity, 52.9% positive predictive value, and 93.3% negative predictive value. These findings suggest that pyuria and microscopic bacteriuria may support preliminary laboratory assessment of suspected UTI, but microscopic urinalysis should not be interpreted as confirmation of clinically diagnosed UTI or as a substitute for urine culture.