Chemical stix testing of urine

Reagent dip-stixs can be used to test for the following chemicals in a fresh urine sample:

• blood
• leukocytes
• protein
• glucose
• ketones
• nitrite
• N-acetyl-B-glucosaminidase
• bilirubin
• urobilinogen

Notes:

• urine-testing strategies for possible UTI in children 3 years or older (1)
  • dipstick testing for leukocyte esterase and nitrite is diagnostically as useful as microscopy and culture, and can safely be used
    • if both leukocyte esterase and nitrite are positive
      • the child should be regarded as having UTI and antibiotic treatment should be started. If a child has a high or intermediate risk of serious illness and/or a past history of previous UTI, a urine sample should be sent for culture
    • if leukocyte esterase is negative and nitrite is positive
      • antibiotic treatment should be started if the urine test was carried out on a fresh sample of urine. A urine sample should be sent for culture. Subsequent management will depend upon the result of urine culture
    • if leukocyte esterase is positive and nitrite is negative
      • a urine sample should be sent for microscopy and culture. Antibiotic treatment for UTI should not be started unless there is good clinical evidence of UTI (for example, obvious urinary symptoms). Leukocyte esterase may be indicative of an infection outside the urinary tract which may need to be managed differently
    • if both leukocyte esterase and nitrite are negative
      • the child should not be regarded as having UTI. Antibiotic treatment for UTI should not be started, and a urine sample should not be sent for culture. Other causes of illness should be explored

Reference:

1. NICE. Urinary tract infection in under 16s: diagnosis and management. NICE guideline NG224. Published July 2022