Is a urinalysis result showing leukocyte (White Blood Cell) esterase, 11-30 White Blood Cells (WBC) and greater than 10 epithelial cells indicative of a urinary tract infection?

Urinalysis Interpretation: 1+ WBC Esterase with 11-30 WBCs and >10 Epithelial Cells

The urinalysis results showing 1+ WBC esterase, 11-30 WBCs, and >10 epithelial cells suggest a contaminated specimen rather than a definitive urinary tract infection. 1, 2

Understanding the Urinalysis Components

• Leukocyte esterase (1+) indicates the presence of white blood cells in the urine, which can suggest inflammation or infection in the urinary tract 1
• The microscopic finding of 11-30 WBCs/HPF is consistent with pyuria, which is typically defined as ≥10 WBCs/HPF in most guidelines 2
• The presence of >10 epithelial cells strongly suggests specimen contamination, which compromises the reliability of the other findings 3

Diagnostic Interpretation

Positive Indicators for UTI:

• Positive leukocyte esterase (1+) has moderate sensitivity (83%) for UTI 1
• WBC count of 11-30/HPF exceeds the threshold for pyuria (>10 WBCs/HPF or >5 WBCs/HPF depending on the guideline) 4

Negative Indicators for UTI:

• High epithelial cell count (>10) strongly suggests contamination of the specimen 3
• No information provided about nitrite test results, which would increase specificity when positive 2
• No clinical symptoms mentioned (dysuria, frequency, urgency), which are essential for diagnosis 1

Clinical Decision Algorithm

1. Assess specimen quality:

   • 10 epithelial cells indicates probable contamination 3

   • This compromises the reliability of both the leukocyte esterase and WBC count

2. Evaluate for clinical symptoms:

   • If asymptomatic: Do not treat as UTI despite positive leukocyte esterase 1
   • If symptomatic (dysuria, frequency, urgency): Consider repeating the test with proper collection technique 5

3. Collection technique considerations:

   • Even with ideal collection technique, false positives are common in disease-free individuals 3
   • Studies show 35-50% of asymptomatic women can have positive leukocyte esterase depending on collection technique 3

Recommendations

• Repeat the urinalysis with proper midstream clean-catch technique to minimize contamination 3
• If repeat specimen still shows high epithelial cells, consider catheterization for a definitive specimen in patients with strong clinical suspicion 5
• Remember that a combination of pyuria and positive leukocyte esterase has better predictive value than either finding alone 6
• In the absence of symptoms, these findings should not be treated as a UTI, regardless of the urinalysis results 1

Common Pitfalls to Avoid

• Do not diagnose UTI based solely on positive leukocyte esterase or pyuria without considering specimen quality 2
• Avoid treating asymptomatic bacteriuria or contaminated specimens, as this contributes to antimicrobial resistance 1
• Remember that epithelial cells >10/HPF significantly reduces the reliability of other urinalysis findings 3
• Do not rule out UTI based on a single parameter; the combination of clinical symptoms and laboratory findings provides the most accurate diagnosis 7