Urinary Tract Infections


What Is the Urinary Tract?

The kidneys filter blood to produce urine. Urine travels from the kidneys down the ureters and into the bladder. The urine is stored in the bladder until urination occurs. The tube through which the urine then passes out of the bladder during urination is called the urethra.

What Is a Urinary Tract Infection (UTI)?

A urinary tract infection is an inflammation of the bladder and the kidneys. It is usually caused by bacteria from the skin outside the urethra moving up the urethra and into the bladder. If the bacteria stay in the bladder, the infection is called cystitis. If the bacteria are in the kidneys, it is called pyelonephritis. These infections are not contagious.

What Are the Symptoms of Urinary Tract Infection?

The signs and symptoms of urinary tract infection in children depend on the child’s age. Symptoms are often misleading. In infants (less than two years old), they are usually nonspecific and may be overlooked. In older children, symptoms may result from irritations caused by bubble baths, poor hygiene or constipation, and may mimic a urinary tract infection. It is essential to obtain a urine culture to avoid missing the diagnosis of UTI, as well as to avoid overdiagnosing UTI in children. 

Symptoms

Infants (Less Than two Years Old)

  • Irritability
  • Vomiting and diarrhea
  • Poor feeding
  • Failure to gain weight

Older Children (More Than two Years Old)

  • Burning with urination
  • Frequent or urgent urination
  • Fever
  • Lower-abdominal pain
  • Wetting episodes
  • Side or back pain

Regardless of age, bladder infection (cystitis) is not usually associated with fever and generally does not produce any long-term damage to the bladder or kidneys. Kidney infection (pyelonephritis), however, is usually associated with a high fever and may produce permanent damage or scarring of the kidney even after only one infection. This is particularly true in the very young child.

How Can I Tell if My Child Has a Urinary Tract Infection?

Your child’s urine will first be evaluated in the office with a microscope. To be certain whether an infection is present, a urine culture will also be obtained. This method is not entirely foolproof, as the urine may be contaminated when voiding by bacteria on the child’s skin. Occasionally, to avoid confusion and to assure greater diagnostic accuracy, a urine sample is obtained by passing a small catheter through the urethra and into the bladder (bladder catheterization).

When Should My Child Be Evaluated for Urinary Tract Infections?

Children who have a culture-proven urinary tract infection should have a radiologic evaluation as soon as possible. This is especially important for infants and small children, since most of them will develop another urinary tract infection. Waiting until a child has had two urinary tract infections before having her/him evaluated increases the risk that permanent kidney damage or scarring may occur. Abnormalities of the urinary tract will be detected in one of three children with documented urinary tract infection.

What Does the Evaluation Consist Of?

A physical examination is not sufficiently accurate in evaluating your child’s urinary tract. The initial study is the kidney sonogram (ultrasound). This test is done to outline the kidneys and ureters so that a blockage or urinary tract defect can be found. This test does not require radiation and is painless. The next study should be a voiding cystourethrogram (VCUG). The (VCUG) is performed by placing a small catheter through the ureter and into the bladder. A fluid (contrast material) is passed through the catheter filling the bladder. A few X-ray pictures are taken during bladder filling and emptying in order to check for reflux of urine. Your child will feel some discomfort but will not need medication for pain. Vesicoureteral reflux, or back flow of urine from the bladder into the ureter and up to the kidney, is the most common problem found. Reflux is dangerous because it allows bacteria which might be in the bladder to reach the kidney. This can cause a kidney infection and kidney damage. A kidney (renal) scan may be done if the above tests are abnormal. This test is used to better demonstrate the actual function and drainage of the kidneys. A kidney scan can also show whether there is kidney damage and scarring. A kidney X-ray (IVP) may be done if the anatomy is not clearly shown on a sonogram or if certain abnormalities are suspected.

How Are Urinary Tract Infections Treated?

Prompt and effective treatment followed by adequate evaluation of the urinary tract is essential to minimize your child’s discomfort and risk of urinary tract damage. Your physician will usually prescribe an oral antibiotic for a period of 5 to 7 days to treat a “simple” UTI. To treat a more “complicated” UTI (babies less than two months old, a child who appears ill, a presence of high fevers, poor response to initial oral antibiotic), your physician may decide to hospitalize your child and begin intravenous antibiotics. In a case where a kidney infection is suspected, the course of antibiotics will be 10 to 14 days. Unfortunately, it is not uncommon for a urinary tract infection to recur (especially in girls) after adequate antibiotic treatment, even with normal radiologic studies. This may be most perplexing to parents and physicians, but there is little chance of significant damage to the urinary system when the radiologic studies are normal. Further invasive studies such as cystoscopy, urethral dilation or repeat VCUG are not indicated or useful. It is important to have your physician perform follow-up urine cultures whether or not another UTI is suspected and routinely every three months for at least one year following treatment. There are children who demonstrate a strong tendency toward recurrent UTIs (more than three per year). Continuous low-dose antibiotic prophylaxis is recommended as a nightly dose for at least three months in these cases. Children with UTIs may have poor voiding habits. These children are often helped by encouraging complete bladder emptying every 3 to 4 hours.