Urinary tract infection (UTI) refers to a bacterial infection in the bladder (cystitis), or kidneys and ureters (pyelonephritis).
Urinary tract infections in childhood are common and can be potentially serious in the first few years of life
The diagnosis of UTI should be considered in all febrile infants and young children, and in all infants with fever without focus
A reliable urine specimen is vital to confirm the diagnosis – urine bags must not be used (high false positive rate)
Suprapubic aspiration is the gold standard in infants less than 6 months, however catheter specimens can be used. In children over 6 months, catheter specimens are the preferred choice if a clean catch specimen has not been achieved by 45 minutes
In febrile young children who have a definite clear alternative clinical diagnosis, it is not necessary to check a urine collection in order to exclude a UTI
Fever may be present, particularly fever without apparent source
Jaundice (in neonates)
In older children symptoms can include dysuria, urinary frequency, and urinary incontinence
Urinalysis – this is not accurate in infants under 12 months – so cannot be used to exclude a UTI. The only urinalysis results reliably predictive of a UTI are the leukocyte esterase and nitrites.
Urine should be sent to the laboratory for microscopy and culture. This must be done urgently in infants < 6 weeks of age in whom a UTI is suspected. After hours a microbiology technician will need to be called in after discussing with the on call Microbiologist.
A reliable urine specimen is vital to confirm the diagnosis – SPA, CSU, clean catch or MSU (in older kids)
Urine cultures may be negative if there is previous antibiotic treatment
Children who are systemically unwell and all infants < 3 mths should have blood tests including: FBC, blood cultures, CRP, U&E
Lumbar punctures should be done in neonates and children < 6 weeks
Investigations for age group
Birth to 6 weeks of age
6 weeks to 3 months of age
Over 3 months of age
FBC, CRP, U&E, blood cultures
Urine – SPA
FBC, CRP, U&E, blood culture
Urine – SPA best, but can do catheter
Consider lumbar puncture only if toxic signs present
Toxic signs present:
FBC, CRP, U&E, blood cultures
Urine – SPA or catheter in children < 6 months, or catheter if you have waited for > 45 mins for a clean catch in older children
All children <3 yrs presenting with a first UTI should have a renal tract US
A renal tract ultrasound is not always necessary for children aged 3 years or older with a simple UTI, however:
Children of any age with recurrent urinary tract infections should have a renal tract ultrasound (non urgent)
Children any age with an atypical UTI or UTI responding poorly to treatment should have a renal tract ultrasound (urgent)
GP Follow Up:
All children presenting with a UTI should have a GP follow up and a GP letter completed (see UTI GP Letter).
In children > 6 mths, GP will arrange an outpatient renal tract US
Referral to General Paediatric Team:
Infants ≤ 6 mths presenting with a UTI should be referred to the General Paediatric Outpatient Clinic at PMH. Complete an internal referral form.
A PMH radiology request form should be completed for a renal tract US, and this placed with the Outpatient Clinic referral form in the ED Consultant’s office. The Consultant checking results will send these off if a UTI is proven on culture.
Advise parents if the US is abnormal, the General Paediatric Team will arrange a clinic follow up.