Routinely review with the culture result (e.g. at around 48 hours) to ensure that the infant or child is responding to treatment, and to reassess the choice of antibiotic. This can be done by telephone:

• What if the infant or child is responding but the culture isolated an organism that is resistant to the chosen antibiotic?
• For upper urinary tract infection, switch to an antibiotic to which the organism is sensitive.
• For lower urinary tract infection, consider completing the course of the original antibiotic and doing a 'test of cure' urine culture when the course has been completed.
• However, some experts recommend always switching to an antibiotic to which the organism is sensitive.
• What if the infant or child is still unwell after 24–48 hours on antibiotic treatment?
• Advise the parents/caregivers to bring him or her in for assessment.
• If an alternative diagnosis is made, manage accordingly.
• If an alternative diagnosis is not made, and:
• Urine culture has isolated an organism resistant to the antibiotic being taken, switch to an antibiotic to which the organism is sensitive.
• Urine culture was not done or does not suggest a more appropriate antibiotic, send a urine sample for culture to identify the presence of bacteria and determine antibiotic sensitivity.
• What if the infant or child has responded well and is no longer symptomatic?
• Do not send urine for culture as a 'test of cure'.
• Do not start prophylactic antibiotics; these are rarely necessary. If prophylactic antibiotics are thought to be indicated, refer or consult a paediatric specialist.

Refer urgently to a paediatric specialist if the infant or child has:

• Poor response to appropriate treatment.
• A history or clinical features suggesting urinary tract obstruction, such as:
• High blood pressure.
• Poor growth.
• Poor urine flow.
• Recurrent fever of uncertain origin.
• Antenatally-diagnosed renal abnormality.
• Family history of vesicoureteral reflux or renal disease.
• Enlarged bladder.
• Abdominal mass.
• Evidence of spinal lesion.

Refer non-urgently to a paediatric specialist if the infant or child:

• Is less than 6 months old, or has:
• Has a history of urinary tract infection (probable or confirmed).

• Infants and children who require imaging tests are included in those who should be referred for specialist assessment.

These recommendations are based on the National Institute for Health and Clinical Excellence guideline Urinary tract infection in children: diagnosis, treatment and long-term management [National Collaborating Centre for Women's and Children's Health, 2007].