Should urine with large leukocytes, 5-10 White Blood Cells (WBCs), and rare bacteria be treated for a Urinary Tract Infection (UTI)?

Management of Urine with Large Leukocytes, 5-10 WBC, and Rare Bacteria

Urine with large leukocytes, 5-10 WBC, and rare bacteria should NOT be treated for a UTI unless the patient has symptoms of a urinary tract infection. 1

Diagnostic Criteria for UTI

Laboratory Findings Interpretation

• The urinalysis findings described (large leukocytes, 5-10 WBC, rare bacteria) without clinical symptoms are insufficient to diagnose a true UTI requiring antibiotics
• Pyuria is defined as ≥10 WBC/high-power field 1, 2
  • The sample in question has 5-10 WBC, which is borderline
  • Large leukocytes on dipstick (leukocyte esterase positive) has sensitivity of 83% but specificity of only 78% 1
• Bacteria without significant pyuria likely represents contamination or colonization 1

Clinical Decision Algorithm

1. Assess for symptoms:

   • Presence of UTI symptoms (dysuria, frequency, urgency, suprapubic pain)
   • Systemic symptoms (fever, flank pain, altered mental status)
   • If NO symptoms → Do not treat (asymptomatic bacteriuria)
   • If symptoms present → Consider treatment based on clinical presentation

2. Consider patient population:

   • Pregnant women: Screen and treat ASB (not applicable to this case)
   • Pre-urologic procedure: Treat ASB (not applicable to this case)
   • All other populations: Do not treat ASB 3

Evidence-Based Recommendations

Asymptomatic Bacteriuria (ASB)

• The Infectious Diseases Society of America (IDSA) strongly recommends against screening for or treating ASB in most populations 3
• Treatment of ASB leads to unnecessary antibiotic use, increased antimicrobial resistance, risk of C. difficile infection, and adverse drug effects 3

Symptomatic UTI Criteria

• True infection requiring treatment is diagnosed by:
  1. Positive urine culture (≥50,000 CFU/mL of a uropathogen)
  2. PLUS systemic symptoms or localized genitourinary symptoms 1
• The combination of leukocyte esterase and nitrite provides the highest diagnostic accuracy for UTI (sensitivity 93%, specificity 72%) 1, 4

Special Considerations

Elderly and Institutionalized Patients

• In older patients with cognitive impairment, bacteriuria with delirium but without local genitourinary symptoms should prompt assessment for other causes rather than antimicrobial treatment 3
• Urinalysis and urine cultures should not be performed for asymptomatic residents in long-term care facilities 3

Catheterized Patients

• For patients with indwelling catheters, ASB should not be screened for or treated 3
• Evaluation is only indicated if there is suspected urosepsis (fever, shaking chills, hypotension, or delirium) 3

Pitfalls to Avoid

1. Overtreating based on laboratory findings alone: Laboratory findings must be interpreted in the context of clinical symptoms
2. Confusing colonization with infection: Bacteria in urine without symptoms is colonization, not infection
3. Failing to obtain urine culture before starting antibiotics: If treatment is indicated, obtain culture first 1
4. Treating based on dipstick alone: Dipstick tests have limitations in accuracy and should be confirmed with microscopy and culture when indicated 4

In conclusion, the described urinalysis findings alone do not warrant antibiotic treatment without corresponding symptoms of UTI. Treatment should be reserved for symptomatic patients to avoid unnecessary antibiotic use and its associated complications.