UTI diagnosis

See NICE 54. Clean catch ideally, pad if clean catch unsuccessful.

See Sofia method of urine collection.

  • Under 3 months – urgent microscopy.
  • 3/12 to 3yrs – arrange microscopy; dipstick is only for where urgent microscopy is not available and low/intermediate risk of serious illness.
    • Microscopy interpretation is simply on basis of pyuria pos/neg, bacteria pos/neg.
  • Over 3yrs – dipstick is standard.

For ambiguous microscopy or dipstick treat according to clinical signs.

Most studies show that clean catch is equivalent to suprapubic aspiration (SPA); limited data on pad, nappy or bag specimens.

  • A positive dipstick urinalysis for BOTH leucocyte esterase (LE) and nitrite is specific, negative both is a good negative predictor. If dipstick positive for just one, not reliable either way. Metanalysis, Huicho Luis, PIDJ 2002;21:1-11. Previous metanalysis by Gorelick and Shaw (Peds 1999) concluded nitrite/LE tests superior to microscopy!
  • Microscopy is more time consuming and expensive to perform than dipstick (but quicker and cheaper than culture). Combination of microscopy for white cells and bacteria can be used accurately to rule in and rule out a UTI. If just one present, not reliable either way.
  • Culture is needed in these in-between cases. Also useful for antibiotic sensitivities.
  • Uricol (Euron, Newcastle) urine pads. Check at 10 min intervals (discard after 30mins). Cost 18p each. Agrees with clean catch for gluc/ket/blood/nitrite (within 1 block ) but in study only 2 cases with leucocytes so ?reliable.

Health Technology Assessment (Winchester, England). 10(36):iii-iv, xi-xiii, 1-154, 2006 Oct.

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