What is the treatment for a urinary tract infection indicated by leukocyte esterase level of 250 and WBC count greater than 182 on urinalysis?

Treatment of Urinary Tract Infection with Elevated Leukocyte Esterase and WBC Count

For a urinary tract infection indicated by leukocyte esterase level of 250 and WBC count greater than 182 on urinalysis, first-line treatment is nitrofurantoin, with trimethoprim-sulfamethoxazole as an appropriate alternative when local resistance rates are below 20%. 1

Diagnostic Confirmation

The urinalysis findings strongly suggest a urinary tract infection:

• Leukocyte esterase level of 250 is significantly positive (sensitivity 72-97%, specificity 41-86%) 1
• WBC count >182 is markedly elevated (normal is <10 WBCs/HPF) 1
• These findings together have high positive predictive value for UTI 2, 3

Treatment Algorithm

First-line options:

1. Nitrofurantoin (100mg twice daily for 5 days)

   • Preferred due to lower resistance rates
   • Good sensitivity against most uropathogens
   • Minimal collateral damage to gut flora 1

2. Trimethoprim-sulfamethoxazole (160/800mg twice daily for 3 days)

   • Effective for UTIs caused by susceptible strains of E. coli, Klebsiella, Enterobacter, Morganella morganii, and Proteus species 4
   • Use only when local resistance rates are <20% 1

3. Fosfomycin (3g single dose)

   • Convenient single-dose therapy
   • Consider for patients who need simplified regimen 1

Second-line options (if first-line contraindicated):

• Amoxicillin-clavulanate (875/125mg twice daily)
  • Effective for complicated UTIs 5
  • Higher risk of adverse effects, particularly diarrhea (15%) 5

Treatment Duration

• Uncomplicated UTI: 3-5 days
• Complicated UTI: 7-14 days
• Adjust based on symptom resolution and risk factors 1

Monitoring and Follow-up

• No need for repeat urinalysis if symptoms resolve 1
• Instruct patients to return if symptoms persist or worsen after 48-72 hours of treatment
• For persistent symptoms, obtain urine culture to guide antibiotic selection 6

Important Considerations

Antibiotic Stewardship

• Adjust empiric therapy based on culture results when available
• De-escalate to narrower spectrum antibiotics when possible 6
• Avoid treating asymptomatic bacteriuria except in pregnancy or before urological procedures 1

Special Populations

• Elderly patients: May present with atypical symptoms; consider longer treatment duration (7 days)
• Pregnant women: Avoid trimethoprim-sulfamethoxazole; beta-lactams are preferred 1, 7
• Catheterized patients: Change catheter before collecting specimen and starting antibiotics 6

Potential Pitfalls

1. Overtreatment: Positive dipstick alone without symptoms may indicate asymptomatic bacteriuria, which generally should not be treated 6, 1
2. Undertreatment: Failure to recognize resistance patterns can lead to treatment failure
3. Inadequate follow-up: Patients should be instructed to seek prompt medical evaluation if symptoms persist or recur 1

Prevention of Recurrence

• Adequate hydration
• Urination after intercourse
• Consider non-antimicrobial measures such as cranberry products or D-mannose for recurrent UTIs 1

The markedly elevated leukocyte esterase and WBC count in this case strongly indicate an active infection requiring prompt antibiotic treatment, with nitrofurantoin being the preferred first-line agent based on current guidelines.