Urinary Tract Infection in Children

This page answers these questions:


What is a Urinary Tract Infection (UTI)?

A UTI is an infection affecting the bladder, kidneys and the tubes carrying urine from the kidneys and bladder (ureters and urethra).

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How do I know my child has a UTI?

Older children will complain of symptoms suggestive of a UTI - they may have:

  • dysuria - pain or discomfort on passing urine
  • frequent urination
  • urgency to get to the toilet - they may have unexpected accidents or wet the bed again
  • tummy pain
  • fever, especially if over 380C with no other cause

In babies and toddlers the symptoms may be less clear and they may have:

  • fever, especially if over 380C with no other cause
  • poor feeding
  • vomiting
  • lethargy and just generally being unwell
  • Irritability
  • Smelly urine - although just having smelly urine in itself doesn't mean a UTI

If the infection involves the upper urinary tract, ie. the kidneys (known as pyelonephritis), your child is more likely to have a high fever (usually above 380C), be generally unwell and may have pain or tenderness in the flank. This is a more serious infection than lower urinary tract infection which just involves the bladder.

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How is a urinary tract infection diagnosed?

A UTI is diagnosed when bacteria are found in a suitably obtained urine specimen. A urine dipstick test gives a guide to how likely an infection is and if it is likely from that test, urine may also be sent to the lab to try and grow bacteria on a broth.

  • In an older child, you will be able to obtain a clean catch urine specimen (they will have alerted you to the fact that they need to go and you can collect the mid stream urine in a sterile container.
  • In toddlers and babies it is more difficult.

    For infants and toddlers over 3 months, a bag urine collection method or a urine collection pad. There can be problems with these specimens if they show bacteria as they may have come from the skin rather than the urinary tract and so a definitive urine test will be needed. However, if there are no bacteria, a UTI is unlikely.

    If you have managed to get a specimen but can't get it to the lab immediately, put the urine in the sterile container in the fridge.
  • In babies less than 3 months of age, because they are so young and serious infection is more likely, they will need a definitive urine test as they may need to start antibiotics immediately - this will usually be performed in hospital by the pediatric team.

A definitive urine test is by a suprapubic aspirate (SPA) where urine is taken directly from the bladder via a needle through the abdomen. Occasionally, the urine will be collected by a catheter going into the bladder rather than the SPA. In these cases, any bacteria are definitely from the urinary tract.

A urine specimen should be checked in all children with:

  • fever more than 380C with no other cause likely
  • any symptoms suggestive of a urinary tract infection

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Who is at risk of having a urinary tract infection?

In the first year of life, any baby can get a urinary tract infection, but some babies are more at risk. They are babies with:

  • poor urine flow - boys should have a urinary stream like a fountain. If not they may have a condition called posterior urethral valves
  • antenatally diagnosed renal abnormality - usually dilated ureters
  • family history of vesico-ureteric reflux or renal disease

In toddlers, urinary tract infections are more common in girls and in those who are constipated. Girls are prone to infection because the urethra is short so the distance from the outside to the bladder is not far and there are many bacteria coming from the back passage which is quite close by.

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What is urinary tract infection treatment?

It depends a bit on the age of your child and if the infection involves the upper urinary tract or not.

  • For infants less than 3 months of age: intravenous antibiotics are usually given in hospital
  • For children older than 3 months of age with an upper UTI (pyelonephritis), antibiotics will be given for 7 - 10 days - they may be oral or start with intravenous.
  • For children older than 3 months of age with an uncomplicated lower urinary tract infection, oral antibiotics are usually given for 3 days.

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Will my child need any special tests after a urinary tract infection?

In the past, children who have had a UTI have had imaging of the kidneys and bladder system looking particularly for vesico-ureteric reflux (when urine passes from the bladder back up toward the kidneys) or scarring of the kidneys. However, more recently, there have been recommendations that mean not all children require investigation - your local center will have guidelines that should be followed.

As a minimum:

  • babies less than 6 months of age should have an ultrasound of the kidneys - this may be within the first few days if there is serious or atypical infection but otherwise will be within 6 weeks. The ultrasound is similar to the ultrasound (sonic) scans you would have had during your pregnancy and will be looking for any sign of dilatation or scars. Those with serious or atypical infection or recurrent infection will also require a DMSA scan, which is a nuclear medicine test (it's safe) looking for scars, and a MCUG (or micturating cystourethrogram) which is when dye is put into the bladder to see if there is back flow towards the bladder (seen in vesicoureteric reflux). The DMSA is performed 4 - 6 months after the infection and the MCUG is usually performed 2 months after the infection.
  • For children older than 6 months but younger than 3 years, those with serious or atypical infection or recurrent infection will require an ultrasound and a DMSA 4 - 6 months later.
  • For children over 3 years of age, those with serious or atypical infection will require an ultrasound. Those with recurrent urinary tract infections will require an ultrasound and a DMSA.

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What else do I need to know if my child has a urinary tract infection?

  • Finish all antibiotic treatment courses
  • If your child is prone to thrush with antibiotics, give a probiotic
  • Keep your child drinking - if it hurts your child to pass urine, put her in the bath to pee
  • Be vigilant and get a urine checked with suggestive symptoms in the future
  • Make sure your child isn't constipated

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  • NICE. UTI in children. August 2007. www.nice.org.uk


To go to the top of the Urinary tract infection, click here

To go to the Infections page, click here

To go to the Pain page, click here

To go to the Constipation page, click here

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Last reviewed 22 May 2011

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Dr Maud MD

Dr Maud MD (MBChB, FRACP, FRCPCH), a specialist pediatrician, provides health information and medical advice for parents of babies and toddlers. Read more about Dr Maud.

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