Test | Details | Advantages | Disadvantages |
---|---|---|---|
Urine sampling | Â | Â | Â |
Suprapubic aspiration (SPA) | Needle attached to syringe inserted through lower abdomen into bladder. | Least risk of contamination | Invasive |
Transurethral catheterisation | Catheter inserted through the urethra into the bladder. | Less invasive than SPA | Invasive, causes pain and distress to child |
Clean voided urine (CVU) | Midstream sample collected in sterile container. | Non-invasive, easy to obtain | Difficult in younger children |
Urine bags | Bag applied to perineum. | Suitable for babies and infants | Risk of contamination |
Urine pads | Absorbent pad placed in nappy. | Â | Â |
Dipstick | Â | Â | Â |
Nitrite | Gram-negative bacteria reduce dietary nitrate to nitrites. | Very easy and quick to perform, relatively cheap | Less accurate than culture |
Leukocyte esterase (LE) Glucose | Leukocyte esterase is an enzyme that suggests the presence of leukocytes. Normal urine contains small amount of glucose. Bacteria metabolise glucose and so this test tests for the absence of glucose. Requires morning fasting urine specimen. | Â | Not commercially available, not suitable for non-potty trained children |
Microscopy | Â | Â | Â |
Pyuria | Urine examined through microscope for presence of white blood cells. Samples may be centrifuged before examination | Quicker than culture | More time consuming than dipstick, more expensive than dipstick and culture |
Bacteriuria | Urine examined for presence of bacteria. Urine may be Gram-stained. | Â | Â |
Culture | Â | Â | Â |
Standard Culture | Reference standard test for UTI. Involves streaking urine on enrichment and selective media. | Very accurate | Time consuming: takes 48 hours to give a result, has to be performed in the laboratory |