• Suspect UTI if the infant or child has any combination of:
• Frequency, dysuria (most common presentation in verbal children).
• Fever without an obvious cause (most common presentation in preverbal children).
• Fever with a presumed cause but poor response to treatment.
• Abdominal pain, loin tenderness.
• Vomiting, poor feeding. Malaise, lethargy, irritability. Haematuria, offensive urine, cloudy urine. Failure to thrive.
• Dysfunctional voiding (voluntary withholding of urine or faeces), incontinence of urine or faeces.

In depth

• Make a preliminary diagnosis on the basis of the clinical symptoms and urgent microscopy (or dipstick test if urgent microscopy is unavailable).
• Confirm the diagnosis with urine culture.

In depth

• Infants and children with suspected urinary tract infection (UTI) are at high risk of serious illness if:
• They are systemically unwell, dehydrated, or vomiting and cannot tolerate oral fluids and medication, or
• Have a history or clinical features suggesting urinary tract obstruction.
• Infants and children with suspected UTI are at intermediate risk of serious illness if:
• They are not at high risk, and they do not satisfy all the criteria for being at low risk.
• Infants and children with suspected UTI are at low risk of serious illness if:
• Temperature is less than 38°C, and there is no loin pain/tenderness.
• Colour, cry, responsiveness, and hydration are normal.

In depth

• Make a working diagnosis of upper UTI (acute pyelonephritis) if there is:
• Fever of greater than 38°C (or history of fever) and bacteriuria, or
• Fever of less than 38°C (and no history of fever), loin tenderness, and bacteriuria.
• Otherwise, diagnose lower UTI (cystitis), which in older children usually presents with specific symptoms (frequency, dysuria, lower abdominal pain).

In depth

• If the child is at high risk for serious illness — urgently refer/admit.
• If the child is at intermediate risk for serious illness — consider urgent referral/admission.

In depth

• If urinary tract infection (UTI) — upper or lower — is suggested by symptoms and supported by urine tests, then treat immediately with an antibiotic.
• Obtain a urine specimen for culture and sensitivities prior to starting antibiotics.
• Delay the decision about treatment until the urine microscopy and culture results are available, when there are no specific symptoms for UTI and:
• Either they are at intermediate risk for serious illness and the urine test does not suggest UTI,
• Or they are at low risk for severe illness (urine test is not needed).

In depth

• Treat with an oral antibiotic for 3 days.
• Consider trimethoprim, cefalexin, amoxicillin, or nitrofurantoin, while taking local bacterial sensitivity patterns into account (this is an off licence use of nitrofurantoin as the summary of product characteristics specifies 7 days).
• Note: avoid using broad spectrum antibiotics (e.g. cephalosporins) when narrow spectrum antibiotics are effective, as they increase the risk of Clostridium difficile, MRSA, and resistant UTIs.
• Treat pain with paracetamol — avoid NSAIDs.
• Encourage (and monitor) adequate fluid intake.

In depth

• Treat with an oral antibiotic for 7–10 days (provided that they do not require admission).
• Consider co-amoxiclav or cefalexin, while taking local bacterial sensitivity patterns into account.
• Treat fever and pain with paracetamol — avoid NSAIDs.
• Encourage (and monitor) adequate fluid intake.

In depth

• They should telephone or return to get the urine culture results when these are expected to be available.
• If the infant or child is still unwell after 24–48 hours, they should return for reassessment.
• Once the infant or child has recovered, they should be alert to the uncommon possibility of a repeat urinary tract infection (UTI). If they suspect a repeat UTI, they should seek medical assessment without delay.
• Infants and children who are 6 months or older, who respond well to treatment and do not have any other unusual features, do not need any further tests unless they have further UTIs.

In depth

• Routinely review with the culture result (e.g. at around 48 hours). This can be done by telephone, but if the infant or child is not responding, they should be brought in for reassessment.
• 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.
• 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.
• Refer non-urgently to a paediatric specialist if the infant or child:
• Is less than 6 months old.
• Has had a previous urinary tract infection.

In depth