What to do next for a patient with abnormal urinalysis results and suspected UTI?

Management of Abnormal Urinalysis with Mixed Genital Flora

A repeat urine specimen should be collected using proper clean-catch technique or catheterization, as the current specimen shows contamination rather than a true urinary tract infection. 1

Understanding Current Results

• The urinalysis shows several concerning findings including positive nitrite, 1+ leukocyte esterase, and few bacteria, suggesting a possible UTI 2
• However, the culture result indicates "mixed genital flora" which strongly suggests specimen contamination rather than a true infection 1
• The presence of squamous epithelial cells in the specimen further supports contamination as the likely explanation 1, 3

Next Steps in Management

For Non-Catheterized Patients:

• Obtain a new urine specimen using proper midstream clean-catch technique with careful perineal cleaning before collection 2, 1
• Provide clear instructions to the patient on proper collection technique, as this significantly reduces contamination rates 4
• If the patient cannot provide a reliable clean-catch specimen, consider in-and-out catheterization for a more definitive specimen 2

Collection Method Based on Patient Factors:

• For male patients: Obtain a midstream clean-catch specimen with proper cleansing or use a clean condom external collection system if the patient is unable to provide a reliable specimen 2
• For female patients: In-and-out catheterization may be necessary if a proper clean-catch specimen cannot be obtained 2

Diagnostic Criteria for UTI

• A true UTI diagnosis requires both:

  1. Evidence of pyuria (presence of WBCs in urine) 2, 5
  2. Significant growth of a single uropathogen (≥50,000 CFU/mL) 1, 5

• The minimum laboratory evaluation for suspected UTI should include:

  1. Urinalysis for leukocyte esterase and nitrite by dipstick 2
  2. Microscopic examination for WBCs 2
  3. Urine culture only if pyuria or positive leukocyte esterase/nitrite is present 2

Treatment Considerations

• Do not treat based on the current results, as they indicate contamination rather than infection 1
• If the repeat specimen shows evidence of UTI, select appropriate antibiotics based on culture and sensitivity results 6, 7
• For uncomplicated UTIs in adults with positive cultures, first-line options include nitrofurantoin, fosfomycin, trimethoprim, or trimethoprim/sulfamethoxazole 6, 7

Common Pitfalls to Avoid

• Treating contaminated specimens leads to unnecessary antibiotic use and potential antimicrobial resistance 1, 7
• Relying solely on dipstick results without proper specimen collection and culture confirmation can lead to misdiagnosis 1, 3
• False-positive urinalysis results are common, even with proper collection techniques 3, 8
• Nitrite test has excellent specificity (98%) but limited sensitivity (53%), while leukocyte esterase has better sensitivity (83%) but lower specificity (78%) 5

By following these guidelines, you can ensure proper diagnosis and management of potential urinary tract infections while avoiding unnecessary treatment of contaminated specimens.