From the Guidelines
A urine test positive for leukocyte esterase and blood is highly suggestive of a urinary tract infection (UTI) and requires prompt medical evaluation and treatment. The presence of leukocyte esterase indicates white blood cells in the urine, pointing to an infection, while blood may suggest inflammation, infection, or injury to the urinary tract 1. According to the clinical practice guideline for the evaluation of fever and infection in older adult residents of long-term care facilities, the minimum laboratory evaluation for suspected UTI should include urinalysis for determination of leukocyte esterase and nitrite level by use of a dipstick and a microscopic examination for WBCs 1.
Key Considerations
- The guideline recommends that if pyuria (≥10 WBCs/high-power field or a positive leukocyte esterase or nitrite test is present on dipstick), a urine culture (with antimicrobial susceptibility testing) should be ordered 1.
- The presence of blood in the urine, along with leukocyte esterase, may indicate a more severe infection or other underlying conditions, such as kidney stones or bladder injury 1.
- Treatment typically involves antibiotics, and the specific antibiotic should be determined by a healthcare provider based on the patient's medical history and local resistance patterns 1.
Recommendations
- Increase fluid intake, especially water, to help flush bacteria from the system.
- Avoid caffeine, alcohol, and spicy foods which can irritate the bladder.
- Complete the full course of antibiotics even if symptoms improve.
- These findings warrant prompt medical attention as untreated UTIs can lead to more serious kidney infections or complications, particularly in pregnant women, elderly individuals, or those with compromised immune systems 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Urine Test Results
- A urine test positive for leukocyte esterase and blood may indicate a urinary tract infection (UTI) 2, 3.
- Leukocyte esterase is a marker that can be used to diagnose UTIs, and its presence in urine can be detected using a dipstick test or a microfluidic paper-based device 2, 3.
- The sensitivity and specificity of the leukocyte esterase dipstick test for diagnosing UTI have been reported to be 63.6% and 44.2%, respectively 2.
- The presence of pyuria (white blood cells in the urine) has been shown to have a higher sensitivity (95.6%) and specificity (60.9%) for detecting UTI than the dipstick test 2.
Diagnosis and Treatment of UTIs
- The diagnosis of UTI is typically based on a combination of symptoms, physical examination, and laboratory tests, including urinalysis and urine culture 4, 5.
- The treatment of UTI usually involves antibiotics, and the choice of antibiotic depends on the severity of the infection, the patient's medical history, and the results of urine culture and sensitivity tests 4, 5, 6.
- Empiric antibiotic therapy may be started before the results of urine culture and sensitivity tests are available, especially in patients with severe symptoms or underlying medical conditions 4, 6.
- The cost-effectiveness of different treatment strategies for UTI has been evaluated, and empiric antibiotic therapy with nitrofurantoin or trimethoprim/sulfamethoxazole has been shown to be a cost-effective option in some cases 6.