II. Mechanism

  1. Some Bacteria reduce urine nitrates to nitrites
  2. Nitrite production typically requires urine standing (in Bladder) for at least 4 hours
    1. Infants do not hold their urine, and do not typically demonstrate nitrite on the urine sample

III. Efficacy

IV. Interpretation

  1. Normal: Negative
  2. Positive
    1. Urinary Tract Infection
    2. Gross Hematuria

V. Causes: False Positive nitrite on Urinalysis

  1. Vaginal contaminant
  2. Phenazopyridine
  3. Dipstick exposed to air
    1. Close test strip containers immediately
    2. Strip exposed to air for 1 week: 33% False Positive
    3. Strip exposed to air for 2 weeks: 75% False Positive

VI. Causes: False Negative Urine Nitrite

  1. Increased Urine Specific Gravity
  2. Increased Urobilinogen
  3. Bacteria lacking nitrate reductase enzyme (e.g. Enterococcus)
  4. Urine pH <6.0
  5. Vitamin C supplementation
  6. Low nitrate diet
  7. Short Bladder incubation time (<4 hours)

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Related Studies

Ontology: Urine dipstick for nitrite (C0430379)

Concepts Laboratory Procedure (T059)
SnomedCT 389742002, 390474004, 302791006
English Urine dipstick for nitrite, Urine dipstick for nitrite (procedure)
Spanish determinación de nitritos en orina con tira reactiva (procedimiento), determinación de nitritos en orina con tira reactiva

Ontology: Urine nitrite (C0580333)

Concepts Laboratory Procedure (T059)
SnomedCT 144810003, 167585009
Italian Nitrito urinario
Japanese 尿中亜硝酸塩, ニョウチュウアショウサンエン
English urine nitrite (lab test), urine nitrite, nitrite level, nitrites urine, nitrite urine, Nitrite urine, Urine nitrite, Urine nitrite (procedure)
Czech Dusitan v moči
Hungarian Nitrit vizeletben
Spanish nitrito en orina, nitrito urinario (procedimiento), nitrito urinario, Nitritos en orina
Portuguese Nitrite na urina
Dutch nitriet urine
French Nitrite dans l'urine
German Nitrite im Urin