II. Mechanism
- Some Bacteria (E. coli, Klebsiella, Proteus) reduce urine nitrates to nitrites
- Many other Bacteria do NOT reduce urine nitrates (e.g. Enterococcus, Pseudomonas, Acinetobacter)
- Nitrite production typically requires urine standing (in Bladder) for at least 4 to 6 hours
- Infants do not hold their urine, and do not typically demonstrate nitrite on the urine sample
III. Efficacy
- Test Specificity: >91%
- Test Sensitivity: <49%
IV. Interpretation
- Normal: Negative
- Positive
V. Causes: False Positive nitrite on Urinalysis
- Vaginal contaminant
- Phenazopyridine
- Dipstick exposed to air
- Close test strip containers immediately
- Strip exposed to air for 1 week: 33% False Positive
- Strip exposed to air for 2 weeks: 75% False Positive
VI. Causes: False Negative Urine Nitrite
- Increased Urine Specific Gravity
- Increased Urobilinogen
- Bacteria lacking nitrate reductase enzyme (e.g. Enterococcus)
- Urine pH <6.0
- Vitamin C supplementation
- Low nitrate diet
- Short Bladder incubation time (<4 hours)
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Related Studies
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 |