Treatment of Leukocyte Esterase Positive Urine Culture
Patients with a leukocyte esterase positive urine culture and symptoms of UTI should be treated with targeted antibiotics based on culture and sensitivity results, with first-line options including trimethoprim-sulfamethoxazole, nitrofurantoin, or cephalexin. 1
Diagnostic Interpretation
The presence of leukocyte esterase in urine indicates pyuria (white blood cells in urine), which is a sign of inflammation in the urinary tract. However, treatment decisions should be based on a combination of factors:
- Diagnostic accuracy: Leukocyte esterase alone has a sensitivity of 83% and specificity of 78% for UTI 1
- Combined testing: When leukocyte esterase is combined with nitrite testing, sensitivity increases to 93% with specificity of 72% 1
- True infection criteria: Requires positive urine culture PLUS systemic symptoms such as fever, new onset flank pain, suprapubic tenderness, or changes in mental status 1
Treatment Algorithm
Confirm true infection:
- Positive leukocyte esterase + symptoms = Treat empirically while awaiting culture
- Positive leukocyte esterase without symptoms = Consider watchful waiting (avoid treating asymptomatic bacteriuria)
Select appropriate antibiotic:
Determine treatment duration:
- Uncomplicated cystitis: 3-5 days
- Complicated UTIs or pyelonephritis: 7-14 days 1
Special Populations Considerations
- Pregnant women: Always treat asymptomatic bacteriuria due to increased risk of pyelonephritis and pregnancy complications 1
- Long-term care facility residents: Avoid testing for and treating asymptomatic bacteriuria 1
- Children: Urine culture is particularly important as pyuria may be absent in certain infections 1
Common Pitfalls to Avoid
- Overtreating asymptomatic bacteriuria: This does not improve outcomes and increases antibiotic resistance 1
- Prolonged therapy: Using antibiotics longer than necessary increases resistance risk
- Fluoroquinolone overuse: Should be avoided as first-line therapy due to resistance concerns 3, 4
- Missing follow-up: No routine follow-up urine cultures are needed if symptoms resolve 1
Antimicrobial Stewardship Principles
- Select the correct drug, dose, and shortest clinically effective duration 3
- Base antibiotic choice on local resistance patterns of uropathogens 3
- Treat only symptomatic UTIs with antibiotics; asymptomatic bacteriuria generally doesn't require treatment 1, 3
- Follow established guidelines for treatment decisions 3
By following this evidence-based approach, you can effectively treat UTIs while practicing good antimicrobial stewardship.