Differential Diagnosis for UA with Positive Leuk and Nit but Culture Negative in an Old Woman
- Single Most Likely Diagnosis
- Asymptomatic Bacteriuria (ASB): This is a common condition in elderly women, where bacteria are present in the urine, but the patient does not exhibit symptoms of a urinary tract infection (UTI). The positive leukocyte and nitrite tests suggest a bacterial presence, but the negative culture may indicate that the bacteria are not pathogenic or that the sample was contaminated.
- Other Likely Diagnoses
- Contaminated Urine Sample: The presence of leukocytes and nitrites may be due to contamination of the urine sample with genital or peri-anal flora, which can lead to false-positive results.
- Interstitial Cystitis: This condition is characterized by chronic inflammation of the bladder, which can cause symptoms similar to a UTI, including positive leukocyte and nitrite tests, but the urine culture is typically negative.
- Atrophic Vaginitis: This condition, common in postmenopausal women, can cause urinary symptoms and positive leukocyte and nitrite tests due to the inflammation of the vaginal mucosa.
- Do Not Miss Diagnoses
- Pyelonephritis: Although the urine culture is negative, pyelonephritis (infection of the kidney) is a serious condition that requires prompt treatment. The presence of leukocytes and nitrites in the urine, along with symptoms such as flank pain and fever, should raise suspicion for this diagnosis.
- Sepsis: In elderly patients, a UTI can quickly progress to sepsis, a life-threatening condition. Even with a negative urine culture, the presence of systemic symptoms such as fever, hypotension, and altered mental status should prompt an evaluation for sepsis.
- Rare Diagnoses
- Tuberculosis (TB) of the Urinary Tract: Although rare, TB can infect the urinary tract and cause symptoms similar to a UTI, including positive leukocyte and nitrite tests, but the urine culture may be negative for common bacteria.
- Fungal Infection: In patients with certain risk factors, such as diabetes or immunosuppression, a fungal infection of the urinary tract can occur, which may not be detected by a standard urine culture.