Pitfalls of diagnosing urinary tract infection in infants and young children

Area of Science:

• Pediatric Nephrology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Urinary tract infections (UTIs) are common pediatric infections.
• Accurate diagnosis of UTI is crucial for timely treatment.
• Pyuria, the presence of white blood cells in urine, is a key indicator for UTI diagnosis.

Purpose of the Study:

• To evaluate the diagnostic accuracy of pyuria for UTI detection in urine collected via transurethral catheterization.
• To assess the reliability of pyuria diagnosis in urine samples collected using a perineal bag.
• To compare the UTI diagnostic performance between different urine collection methods.

Main Methods:

• A study involving 301 patients with suspected UTI between 2005 and 2009.
• Collection of 438 urine samples using transurethral catheterization.
• Analysis of pyuria in both catheterized and bag-collected urine specimens to determine UTI diagnostic accuracy.

Main Results:

• The false-negative rate for UTI diagnosis based on pyuria in catheterized urine was 9.0%.
• Approximately 28% of pyuria-positive bag-collected samples were pyuria-negative by catheterization.
• This discrepancy was significantly higher in girls (56.7%) compared to boys (8.9%).

Conclusions:

• Absence of pyuria in catheterized urine does not exclude a UTI diagnosis.
• Pyuria in bag-collected urine may include leukocytes from external genitalia, affecting diagnostic reliability.
• Transurethral catheterization provides a more accurate assessment of pyuria for UTI diagnosis than bag collection, particularly in differentiating true infection from contamination.