A urinary tract infection (UTI) is a bacterial infection of the urinary tract. This article discusses UTIs in children.

The urinary tract includes the:

• Bladder
• Kidneys
• Ureters -- the tubes that take urine from each kidney to the bladder
• Urethra -- the tube that empties urine from the bladder to the outside

See also:

• Catheter-associated UTI
• Kidney infection
• Urinary tract infection - adults

Most urinary tract infections (UTIs) occur in the lower urinary tract, which includes the bladder and urethra. In most cases, bacteria infects the area, and leads to inflammation.

In boys, UTIs are most common before the first birthday. In young girls, UTIs are most common around age 3, around the time they begin toilet training.

UTIs in children may be caused by problems in the urinary tract, including vesicoureteral reflux -- a problem with a valve in the bladder that allows urine to back up into the ureters and kidneys.

The following increase a child's chance of developing a UTI:

• Constipation
• Enlarged bladder
• Family history of vesicoureteral reflux or kidney disease
• Fever that keeps returning and has no clear cause
• Growth (mass) in the abdomen
• High blood pressure
• History of UTI
• Myelomeningocele or other defect of the spine
• Poor growth
• Poor urine flow
• Problems urinating (dysfunctional voiding)
• Structural problem in the urinary tract

Young children with UTIs may only have a fever, or no symptoms at all.

Symptoms of a UTI in children include:

• Blood in the urine
• Chills with shaking
• Cloudy urine
• Fever
• Flushed, warm, or reddened skin
• Foul or strong urine odor
• Frequent or urgent need to urinate
• General ill feeling (malaise)
• Lethargy
• Nausea
• Pain in the side (flank) or back
• Pain or burning with urination
• Pressure in the lower pelvis
• Severe pain in the belly area
• Urinary incontinence after the child has been toilet trained
• Vomiting

A urine sample is needed to diagnose a UTI in children. The sample is examined under a microscope and sent to a lab for a urine culture.

In children who are not toilet trained, getting a urine sample can be difficult. The test cannot be done using a wet diaper. Possible ways to collect a urine sample in very young children include:

• Urine collection bag -- A special plastic bag is placed over the child's penis or vagina to catch the urine; this is not the best method because the sample may become contaminated.
• Catheterized specimen urine culture -- A plastic tube (catheter) placed into the tip of the penis or into the vagina collects urine directly from the bladder.
• Suprapubic urine collection -- A needle is placed through the skin of the lower abdomen and muscles, into the bladder, and used to collect urine.

If this is your child's first UTI, special imaging tests may be done to determine why the infection occured. Tests may include:

• Kidney ultrasound
• X-ray taken while the child is urinating (voiding cystourethrogram)

These studies may be done while the child has an infection, or weeks to several months afterward.

Your doctor will consider many things when deciding if and when a special study is needed, including:

• Is the child younger than 6 months?
• Has the child had infections in the past?
• Is the infection severe?
• Does the child have other medical illnesses?
• Does the child have a problem with the spinal cord or defects of the urinary tract?
• Has the child responded quickly to antibiotics?

In children, UTIs should be treated quickly with antibiotics to protect the developing kidneys. Any child under 3 to 6 months or who has other complications should see a specialist immediately.

Younger infants will usually stay in the hospital and be given antibiotics through a vein. Older infants and children are treated with antibiotics by mouth. If this is not possible, they are admitted to the hospital where they are given antibiotics through a vein.

Some children may need to take antibiotics for long periods of time (as long as 6 months - 2 years), or they may be prescribed stronger antibiotics. The health care provider may also recommend low-dose antibiotics after the first symptoms have gone away.

Antibiotics commonly used in children include:

• Amoxicillin or amoxicillin/clavulanic acid (Augmentin)
• Cephalosporins
• Doxycycline (should not be used in children under age 8)
• Nitrofurantoin
• Trimethoprim-sulfamethoxazole

Follow-up urine cultures may be needed to make sure that bacteria are no longer in the bladder.

Most children are cured with proper treatment. The treatment may continue over a long period of time.

The long-term consequences of repeated UTIs in children can be serious. However, these infections can usually be prevented.

• High blood pressure
• Kidney abscess
• Kidney infection (pyelonephritis)
• Renal insufficiency or kidney failure
• Swelling of the kidneys (hydronephrosis)

Call for an appointment with your health care provider if your child's UTI symptoms continue after treatment or come back more than two times in 6 months.

Call your health care provider if the child's symptoms get worse, or new symptoms develop, especially:

• Back pain or flank pain
• Persistent fever
• Vomiting

• Avoid giving your child bubble baths.
• Increase the child's intake of fluids.
• Keep your child's genital area clean to prevent bacteria from entering through the urethra.
• Wipe the genital area from front to back to reduce the chance of spreading bacteria from the rectal area to the urethra.

Long-term use of preventive (prophylactic) antibiotics may be recommended for some children who are prone to chronic UTIs.

Roussey-Kesler G, Gadjos V, Idres N, Horen B, Ichay L, Leclair MD, et al. Antibiotic prophylaxis for the prevention of recurrent urinary tract infection in children with low grade vesicoureteral reflux: results from a prospective randomized study. J Urol. 2008;179:674-679; discussion 679. Epub 2007, Dec 20.

Shaikh N, Morone NE, Lopez J, Chianese J, Sangvai S, D'Amico F, Hoberman A, Wald ER. Does this child have a urinary tract infection? JAMA. 2007; 298:2895-2904.

Mori R. Kakhanpaul M, Verrier-Jones K. Diagnosis and management of urinary tract infection in children: summary of NICE guidelines. BMJ. 2007; 335:395-397.