Should a patient with a urinalysis showing mild leukocyturia (5-10 White Blood Cells (WBC)), mild hematuria (5-10 Red Blood Cells (RBC)), and bacteriuria (1+ bacteria), but negative leukocyte esterase and nitrates, be treated for a urinary tract infection (UTI)?

Should This Urinalysis Be Treated?

No, this urinalysis should not be treated with antibiotics unless the patient has specific urinary symptoms (dysuria, frequency, urgency, fever, or gross hematuria). The negative leukocyte esterase effectively rules out a true urinary tract infection in most cases, and the findings likely represent either specimen contamination or asymptomatic bacteriuria, neither of which warrants antimicrobial therapy. 1, 2

Critical Diagnostic Interpretation

The negative leukocyte esterase is the most important finding in this urinalysis and has excellent negative predictive value (82-91%) for ruling out UTI. 2 When both leukocyte esterase and nitrite are negative, UTI is effectively ruled out in most populations with a negative predictive value of 90.5%. 2

Why These Findings Don't Indicate True Infection

• The 5-10 WBC/hpf count is below the diagnostic threshold for significant pyuria, which requires ≥10 WBCs/hpf in most guidelines. 1, 2
• Negative leukocyte esterase strongly suggests asymptomatic bacteriuria rather than active infection, as leukocyte esterase distinguishes true UTI from colonization. 2, 3
• The presence of bacteria with negative leukocyte esterase indicates colonization (asymptomatic bacteriuria) in 10-50% of certain populations, particularly elderly patients. 3
• The 5-10 RBC/hpf is non-specific and does not contribute to UTI diagnosis without other supporting findings. 1

Symptom-Based Decision Algorithm

If Patient is ASYMPTOMATIC:

• Do not order urine culture 2
• Do not initiate antibiotics 2, 3
• No further workup is needed unless symptoms develop 2
• Treating asymptomatic bacteriuria provides no clinical benefit and increases antimicrobial resistance 3

If Patient HAS Specific Urinary Symptoms:

Look for these specific symptoms: 2

• Dysuria (>90% accuracy for UTI when present) 2
• Urinary frequency or urgency 2
• Fever >37.8°C 2
• Gross hematuria 2
• New or worsening urinary incontinence 2

If symptomatic, obtain a properly collected urine culture before starting antibiotics. 1, 2 Use midstream clean-catch or catheterization to avoid contamination. 2

Common Pitfalls to Avoid

• Do not treat based on bacteria alone without pyuria and symptoms - this represents asymptomatic bacteriuria in most cases. 2, 3
• Do not attribute non-specific symptoms (confusion, functional decline, malaise) to UTI without specific urinary symptoms, especially in elderly patients. 2, 3
• Do not rely on negative nitrites to rule out infection - nitrites have only 19-53% sensitivity, though the negative leukocyte esterase is more reliable here. 1, 2
• Do not accept contaminated specimens - the low WBC count with bacteria suggests possible contamination; if clinical suspicion is high, recollect the specimen properly. 2

Special Population Considerations

Elderly/Long-Term Care Residents:

• Asymptomatic bacteriuria prevalence is 10-50% in this population 3
• Evaluate only with acute onset of specific urinary symptoms 2
• Untreated asymptomatic bacteriuria persists for 1-2 years without increased morbidity or mortality 3

Catheterized Patients:

• Bacteriuria and pyuria are nearly universal with chronic catheterization 3
• Do not screen for or treat asymptomatic bacteriuria (Level A-I evidence) 3
• Treatment promotes antimicrobial resistance without clinical benefit 3

Febrile Infants <2 Years:

• This population requires both urinalysis AND culture before antibiotics, as 10-50% of UTIs have false-negative urinalysis 2
• Use catheterization or suprapubic aspiration for specimen collection 2

When to Reconsider

If strong clinical suspicion exists despite these findings:

• Obtain a new, properly collected specimen (catheterization in women if needed) 2
• Order urine culture with antimicrobial susceptibility testing 1, 2
• Consider non-urinary sources of symptoms 2
• In suspected pyelonephritis or urosepsis (fever >38.3°C, hypotension, rigors), proceed with culture regardless of urinalysis results 2