Urinary tract infection (UTI) in children | Pokenga pūaha mimi

Key points about urinary tract infections in children

  •  A urinary tract infection (UTI) is an infection in the urine (wee).
  • UTIs are common in tamariki and can cause them to have high temperatures and become unwell.
  • Sometimes UTIs can make pēpi and young tamariki seriously ill.
  • Pēpi under 12 months of age need investigation after a UTI to see if anything is wrong with their urinary tract.
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The urinary tract is the kidneys, ureters, bladder, and urethra.

The kidneys filter and remove waste and water from the blood to produce urine. The urine travels from the kidneys down 2 narrow tubes called the ureters. The urine is then stored in the bladder.

When your child does a wee, urine flows out of the body through the urethra, a tube at the bottom of the bladder. The opening of the urethra is at the end of the penis in boys and in front of the vagina in girls.


Image credit: 123rf

A UTI (urinary tract infection) is an infection in the urine (wee). It usually starts in the bladder and sometimes affects the kidneys.

It usually develops when germs (bacteria) from their poo, which are on the skin, get into the urethra and the bladder. This can happen to any baby or child and is not due to poor hygiene.

UTIs are common. They are most common in babies under the age of 12 months but can affect tamariki of any age.

There are some conditions which make pēpi and tamariki more likely to get UTIs:

  • constipation (problems in passing poo)
  • an abnormality of the urinary tract
  • neurological conditions where their bladder doesn't empty properly.

Symptoms in tamariki

Children with a UTI may have the following symptoms:

  • fever
  • vomiting
  • feeling generally unwell often with loss of appetite
  • pain on doing a wee
  • wanting to wee frequently (but not much wee coming out)
  • pain in the lower part of the tummy or the lower back
  • smelly, cloudy wee
  • blood in the wee
  • bedwetting or wetting during the day, if previously dry.

If you think your child has a UTI, see your healthcare provider or an after-hours medical centre. 

Symptoms in pēpi and young tamariki

Babies and young children can't tell you about their discomfort when doing a wee and you may not notice them going more often. Signs of a UTI in babies and young children can include:

  • fever (with no obvious cause such as a rash or cough)
  • irritability
  • poor feeding
  • vomiting
  • being very tired and lacking energy (lethargic)
  • poor weight gain
  • jaundice in newborn babies which continues for more than 2 weeks.

Signs of more serious infection in young babies and children

Sometimes a simple UTI can become more serious in young babies or children when the infection spreads to involve the kidneys, or spreads into the blood stream. Signs of this can include:

  • high fever
  • not feeding
  • tummy pain
  • repeated vomiting
  • shivering
  • drowsiness.

If this happens, see your healthcare provider or after-hours medical centre urgently.


Testing your child's urine is the only way to know for sure if they have a UTI. Your healthcare provider can arrange a urine test for your child.



Antibiotics are the main treatment for UTIs. Treatment is usually for 3–7 days. This depends on several factors, including how unwell your child is and whether they have underlying kidney problems.

Your child's symptoms should start to improve after 48 hours of antibiotic treatment.

Drinking more fluids

Encouraging your child to drink more fluid may help.

Paracetamol if needed

You can give pain relief (paracetamol) if your child is in discomfort. You must follow the dosage instructions on the bottle. It is dangerous to give more than the recommended dose. Here is a paracetamol dose calculator so you can work out how much to give them.

Some pēpi and tamariki need to go to hospital

The following babies and children with a UTI usually need to go to hospital to see if they need intravenous antibiotics (given directly into a vein):

  • Young pēpi under 3 months of age.
  • Tamariki who are very unwell.

If your baby has had a UTI and is under 12 months of age, they may need further tests.

Renal ultrasound scan

The most common investigation is a renal ultrasound. This can find any blockages and checks that the kidneys are normal in shape, size and position. Read more about renal ultrasounds(external link).

Other investigations

A small number of babies and children may need an MCU (micturating cysto-urethrogram) or a nuclear medicine scan. A specialist at the hospital needs to request these tests. Read more about MCU(external link) and nuclear medicine scans(external link)

Suggestions that may help some children

Parents often want to know what they can do to prevent UTIs. Not all UTIs can be prevented, but here are some suggestions that may help some children:

  • Treat any constipation – children who have constipation are at higher risk of developing a UTI.
  • Encourage your child to go to the toilet regularly when they feel the need (children who hold on a long time are more at risk of UTIs).
  • Encourage your child to sit properly on the toilet with their feet on a stool so that they empty their bladder completely.
  • Make sure your child drinks plenty of water with meals, and during hot weather.
  • Teach girls to wipe their bottoms from front to back rather than back to front (to reduce the spread of germs from the bowel to the opening of the urethra).
  • Make sure your child drinks plenty of water with meals and during hot weather. 

UTIs in boys

There is a suggestion in studies of UTI in boys that circumcision might slightly reduce the incidence of UTI. But the benefit is small. Most specialists would not recommend circumcision for this reason unless they are having repeated UTIs which are causing major health problems.

Avoiding things that may irritate your child's bottom

Try to avoid anything that may cause irritation to your child's bottom:

  • Avoid giving your child bubble baths, especially if they have sensitive skin.
  • Wash your child's hair in the shower rather than in the bath so they don't sit in soapy water.
  • Check for threadworms, which are very common in children, and consider treating your child every 6 months.
  • Encourage girls to wear cotton underwear.

Image credit: Healthify He Puna Waiora

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Credits: Content shared between HealthInfo Canterbury, KidsHealth and Healthify He Puna Waiora as part of a National Health Content Hub Collaborative.

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