What is the appropriate management for a patient with a positive leukocyte esterase result and negative bacteria in urinalysis?

From the Guidelines

For patients with a positive leukocyte esterase result and negative bacteria in urinalysis, management should be guided by the presence or absence of symptoms, with empiric antibiotic therapy recommended for symptomatic patients while awaiting urine culture results. The presence of leukocyte esterase indicates inflammation in the urinary tract, which could be due to various causes including infection, contamination, or non-infectious conditions 1.

Key Considerations

• Symptomatic patients (with symptoms such as dysuria, frequency, urgency) should be treated with empiric antibiotic therapy.
• First-line antibiotic options include nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin.
• Asymptomatic patients are generally not recommended for antibiotic therapy, as this likely represents asymptomatic pyuria rather than true infection.
• Urine culture remains the gold standard for confirming infection, and a clean-catch midstream urine sample should be collected for culture before starting antibiotics when feasible.

Approach to Management

• For symptomatic patients, start empiric antibiotic therapy while awaiting urine culture results.
• For asymptomatic patients, monitor and possibly retest if concerns persist, rather than initiating antibiotic therapy.
• Consider the potential for early infection, partially treated infection, non-infectious inflammation, contamination, or certain non-bacterial infections like chlamydia or tuberculosis in patients with positive leukocyte esterase and negative bacteria on urinalysis 1.

From the Research

Management of Positive Leukocyte Esterase with Negative Bacteria in Urinalysis

• The presence of positive leukocyte esterase with negative bacteria in urinalysis can indicate a urinary tract infection (UTI), but the results must be interpreted in the context of the patient's symptoms and pretest probability 2.
• A positive leukocyte esterase result can increase the probability of UTI, but initiation of treatment should take into account the risk of UTI based on symptoms as well 2.
• In cases where the probability of UTI is moderate or unclear, urine culture should be performed, as it is the gold standard for detection of UTI 2.
• The choice of antibiotic treatment depends on the suspected causative agent and local patterns of antibiotic resistance, with nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole being common first-line treatments 2, 3, 4.
• A study comparing 5-day nitrofurantoin with single-dose fosfomycin found that nitrofurantoin resulted in a significantly greater likelihood of clinical and microbiologic resolution at 28 days after therapy completion 4.
• Nitrofurantoin is considered a effective drug in the treatment of acute urinary infection, but its use should be carefully considered in cases of chronic UTI due to potential long-term side effects 5.

Diagnostic Considerations

• Leukocyte esterase is a useful marker for diagnosing UTIs, and quantitative determination of this biomarker can be achieved using microfluidic paper-based devices 6.
• The development of sensitive and quantitative diagnostic methods for UTIs is important for accurate diagnosis and treatment, especially in cases where symptoms are unclear or moderate 2, 6.
• Urine culture remains the gold standard for detecting UTIs, but dipstick urinalysis and other diagnostic methods can provide useful information for guiding treatment decisions 2, 3.