Urinary tract infections in children

Urinary tract infections (UTIs) are relatively common in children, particularly young children still in nappies. Girls are more likely than boys to develop a UTI, except in the first 6 weeks of life, when boys seem to be more susceptible.

The most common organisms that infect the urine are bacteria that normally live in the bowel. Wiping your child's bottom from the front to the back (rather than from back to front) can help prevent carrying bacteria from the bowel to the urinary tract.

UTIs, especially ones that recur, can also be caused by your child’s bladder not emptying properly or sometimes by structural problems of the kidneys or bladder.

Symptoms of a UTI

Symptoms of a UTI can vary. In infants and young children, symptoms can include fever, irritability, vomiting or diarrhoea, poor feeding or failure to put on weight. As children get older, the symptoms often become more specific, such as pain on passing urine, accidentally wetting themselves (especially during the day rather than at night) when they’ve been toilet trained previously, abdominal pain, and going to the toilet more frequently than usual. Fever may or may not be present.

Diagnosis of a UTI

To diagnose a UTI, your doctor will need to send a urine specimen to the laboratory for testing. In older children, this can easily be done by collecting a sample in a specimen jar as your child passes urine into the toilet.

In younger children, urine samples can be more difficult to collect. Very occasionally, your doctor may need to insert a tube (catheter) through the urethra into your child’s bladder, or pass a fine needle into the bladder through the wall of the abdomen to collect a sample.

So called ‘bag urines’, where an adhesive plastic collecting bag is used to collect urine, frequently yield contaminated samples which cannot provide a diagnosis; if this method is used, it’s best that a nurse or doctor performs the collection rather than trying to do it yourself at home.

Treatment

If the child is unwell and a UTI is strongly suspected, your doctor may prescribe antibiotics as soon as the urine specimen is collected. Otherwise your doctor may wait until the result of urine culture is known. Commonly the antibiotics are given by mouth but, in some cases, such as in children who are extremely unwell or in very young infants, the antibiotics will be given via a drip, and the child will need to be in hospital.

Underlying kidney and bladder problems

Most children diagnosed with their first UTI need to be tested for problems with their kidneys or bladder. Up to one-third of children with a UTI will have an underlying kidney or bladder problem. The tests usually include a kidney ultrasound, with or without a bladder X-ray, known as a micturating cysto-urethrogram (MCU).

In an MCU, a catheter is passed into the bladder and dye is injected through it. It will show what happens when your child passes urine and whether urine is flowing back up the ureters towards the kidneys rather than being passed straight down the urethra. This abnormal flow of urine is called urinary reflux or sometimes vesico-ureteric reflux.

Urinary reflux can be harmful because it not only predisposes your child to infection (because of some urine always being left in the bladder) but it can also contribute to scarring of the kidneys if the reflux is severe.

The treatment of vesico-ureteric reflux may involve long-term antibiotics to prevent recurrent infections. Usually with time, the reflux will improve by itself. In some severe cases, surgery may be needed to treat the reflux.

Last Reviewed: 12 February 2010
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References

1. Urinary tract infections: children (revised June 2010). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2011 Nov. http://online.tg.org.au/complete/ (accessed Mar 2012).
2. The Royal Children’s Hospital Melbourne. Clinical Practice Guidelines: Urinary tract infection (updated April 2011). http://www.rch.org.au/clinicalguide/cpg.cfm?doc_id=5241 (accessed Mar 2012).
3. The Royal Children’s Hospital Melbourne. Kids Health Info: Urinary tract infection (UTI) (updated October 2010). http://www.rch.org.au/kidsinfo/factsheets.cfm?doc_id=3736 (accessed Mar 2012).
4. Mayo Clinic.com. Vesicoureteral reflux (last updated 16 Jul 2011). http://www.mayoclinic.com/health/vesicoureteral-reflux/DS00999 (accessed Mar 2012).
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