Comparison of Urine Dipstick and Urine Sediment Microscopy With Culture for Diagnosing Pediatric Urinary Tract Infections: A Retrospective Cross-Sectional Study at Tikur Anbessa Hospital, Ethiopia

TL;DR

This study compares urine dipstick and microscopy tests with urine culture for diagnosing UTIs in children in Ethiopia, finding that while rapid tests are fast and cost-effective, they lack accuracy and require confirmation.

Contribution

The study evaluates the diagnostic performance of rapid UTI tests in a resource-limited Ethiopian hospital setting.

Findings

Dipstick nitrite had high specificity but low sensitivity, while leukocyte esterase showed moderate sensitivity and specificity.

Urine WBC microscopy had 67% sensitivity and 73.2% specificity but a 33% false-negative rate.

Culture positivity was higher in females, and rapid tests had sex-based differences in performance.

Abstract

Urinary tract infections are common in children, and early diagnosis is crucial to prevent long-term complications such as renal scarring. While urine culture remains the gold standard, its 24–72-h turnaround time can delay treatment. To expedite diagnosis, rapid tests such as urine dipstick and microscopy are commonly used, but their reliability in resource-constrained settings like Ethiopia is uncertain. This study is aimed at comparing the diagnostic performance of these rapid tests with urine culture in pediatric patients.

A retrospective cross-sectional study was conducted at Tikur Anbessa Specialized Hospital, Ethiopia, from September 2021 to September 2022. The diagnostic performance of urine dipstick tests (nitrites and leukocyte esterase) and urine microscopy for white blood cells (WBCs) was compared to urine culture results, with sensitivity, specificity, PPV, NPV, and diagnostic accuracy calculated.

A total of 224 children (mean age 5 years; 50% < 4 years) were included in the final analysis. Dipstick nitrite positivity was low (10.9%), limiting its reliability. Leukocyte esterase positivity was higher in males (56%) than in females (43.2%), with an overall rate of 51.8%. Urine WBC microscopy showed higher positivity in males (52.7%) than in females (35.1%). Urine culture had a higher positivity rate in females (55.4%) than in males (47.3%), with an overall rate of 50%. Dipstick nitrite had high specificity (94.6%) but low sensitivity (16.1%), while leukocyte esterase had moderate sensitivity (59.8%) and specificity (75.9%). Combining dipstick tests improved sensitivity (61.6%) but reduced specificity. Urine WBC microscopy showed 67.0% sensitivity, 73.2% specificity, and 70.1% accuracy, with a 33% false-negative rate.

Dipstick nitrites and leukocyte esterase offer a rapid, cost-effective way to detect UTIs in children and guide early treatment, but their limited specificity necessitates confirmatory tests like urine culture or WBC microscopy. Future research should explore novel urinary biomarkers to improve accuracy, minimize invasiveness, and account for age- and sex-specific differences.