Urinary Tract Infections in Children - Exams and Tests

Exams and Tests

Initial tests

If your child has symptoms of a urinary tract infection (UTI), the doctor's initial evaluation will probably include:

• A medical history and physical exam.
• Urinalysis, which measures different parts of urine to help identify a UTI.
• Urine culture, which detects and identifies the bacteria that are causing a UTI.

If the doctor suspects that your child has a UTI, a urinalysis will help point to a diagnosis. A urine culture can confirm the diagnosis and identify what is causing the infection. However, the results usually are not available for a couple of days. Rather than delaying treatment to wait for the results of the urine culture, the doctor probably will start your child on antibiotics if your child's symptoms, history, and urinalysis make the presence of a UTI likely.

One of several methods may be used to collect the urine sample.

• Older children may urinate into a container.
• In babies and young children, the doctor may:
  • Insert a catheter through the urethra and into the bladder to collect urine.
  • Collect urine by attaching a bag around the child's genitals until the child urinates. However, the risk of having other substances get into (contaminate) the urine sample is extremely high with this method.
  • Insert a needle through the abdomen directly into the bladder (suprapubic aspiration) to obtain the sample.

The doctor may do other tests if your child has a UTI and:

• Does not improve after 4 days of antibiotic treatment.
• Has a known abnormality of the urinary tract or a history of certain kidney or bladder problems that could make the infection harder to treat.
• May be infected with unusual bacteria that won't respond to the usual treatment.
• Shows signs of kidney failure.

These other tests may include kidney (renal) ultrasound to identify the cause of blocked urine flow in a kidney and voiding cystourethrogram to detect obstructions and vesicoureteral reflux.

Tests after a child's first UTI

Some doctors recommend an evaluation of the urinary tract after the first UTI in an infant or young child. The American Academy of Pediatrics recommends evaluation after a first UTI for children ages 2 months to 2 years in particular. But a study reports that these tests may not provide information that helps with treatment plans.¹ The most common tests after an infant's or young child's first UTI are:

• Kidney (renal) ultrasound. The doctor may review a fetal ultrasound that was done during the mother's third trimester of pregnancy, if available.
• Voiding cystourethrogram, which is an X-ray test that takes pictures of your child's bladder and urethra during urination.

The purpose of doing these tests after treatment for your child's UTI is to reduce the risk of future kidney damage and related problems, such as high blood pressure and kidney failure. These tests can identify vesicoureteral reflux, abnormalities of the urinary tract, and other conditions that may make your child more prone to kidney infections. If the tests identify any of these conditions, the doctor can monitor and give preventive treatment, if needed, to your child. The doctor will do these tests at the earliest convenient time after your child's UTI improves.

The doctor may do a kidney scan (renal scintigram) to evaluate persistent kidney infection or to evaluate kidney scarring or damage caused by previous infection.

During the year after your child's first UTI, the doctor may do periodic urine cultures to screen for UTI infections. But doctors do not agree on the effectiveness of follow-up urine cultures.²