Urinary Tract Infection Overview


The urinary system includes two kidneys (that filter urine), two ureters (that move urine from the kidneys to the bladder), the bladder (that holds urine), and the urethra (that carries urine out of the bladder). Bacteria (germs) do not normally live in these areas. When bacteria enter the bladder or kidneys, an infection can develop. These infections are called urinary tract infections (UTI).

Kidney infections are the most serious type of UTI because, if not treated quickly, the infection can permanently damage the kidneys. Rarely, damage to the kidney can lead to high blood pressure and kidney failure later in life.


In healthy children, most urinary tract infections (UTI) are caused by Escherichia coli (E. coli) bacteria, which are normally found in stool. These bacteria can move from the anus to the urethra and into the bladder (and sometimes up into the kidney) causing infection.

Risk factors

Some children have a higher chance of developing a UTI. The following are some risk factors for UTI:

  • Young age; boys younger than one year old, and girls younger than four years of age are at highest risk.
  • Being uncircumcised; there is a four to 10 times higher risk of UTIs in uncircumcised boys. Still, most uncircumcised boys do NOT develop UTIs.
  • Having a bladder catheter for a prolonged period of time.
  • Having parts of the urinary tract that did not form correctly before birth.
  • Having a bladder that does not work properly.
  • Having one UTI slightly increases the chance of getting another UTI.


Symptoms of a urinary tract infection depend on the child’s age.

Older children

Children older than two years often have:

  • Pain or burning when urinating
  • Frequent need to urinate
  • Pain in the lower abdomen or sides of the back
  • Fever (higher than 100.4ºF or 38ºC)

Younger children

Symptoms in children younger than two years may include one or more of the following:

  • Fever, which may be the only symptom
  • Vomiting or diarrhea
  • Irritability or fussiness
  • Poor feeding, poor weight gain


If you are concerned that your child has a urinary tract infection (UTI), make an appointment with the child’s doctor or nurse within 24 hours. Waiting to start treatment can increase the risk of damage to the kidneys.

Urine testing

A urine sample is needed to determine if the child has a UTI. In young children who are not toilet trained, initial testing may be performed on a urine sample collected in a bag. However, if those results suggest that the child has a UTI, it is usually necessary to insert a thin sterile tube (a catheter) into the bladder to obtain a urine sample for the urine culture. The use of bags to collect urine for urine culture is discouraged because the results are often misleading.

In older children who can use the toilet, you can collect a urine sample by having the child urinate into a sterile cup.

After obtaining the urine, a urine dipstick test is usually done in the office. If the test suggests a UTI or the child has UTI symptoms, the doctor or nurse will send the urine sample to a lab for urine culture to confirm the diagnosis. The culture helps decide which antibiotic is best. It takes up to 48 hours for germs to grow, so the culture results are not available right away.

Based on the child’s symptoms and the results of the dipstick test, the doctor or nurse may decide to start antibiotics before urine culture results are available.

Imaging tests

Imaging tests, such as ultrasound, can show if a child’s urinary system did not form correctly before birth. If the urinary system is abnormal, a child is more likely to have UTIs. A kidney ultrasound is generally done in younger children (less than three to five years old). Children who have had more than one UTI generally have more detailed imaging tests (a voiding cystourethrogram [VCUG] test) to look for abnormalities that may have been missed by the ultrasound.

Kidney ultrasound

Ultrasound uses sound waves to create a picture of the kidneys. During the test, gel is applied to the skin on the child’s back and abdomen and a small wand-like device is pressed against the body. The test is not painful and usually takes less than 30 minutes.

Voiding cystourethrogram

A voiding cystourethrogram (VCUG) is an x-ray test that shows the outline of the child’s bladder and urethra. The test can also show if urine flows from the bladder backwards into the ureters or kidneys; this is called vesicoureteral reflux. Reflux may increase the chance that a child will have kidney infections.

This test takes about one to two hours to complete and involves putting a catheter into the child’s bladder. Dye is put into the child’s bladder through the catheter and x-rays are taken before and after the child urinates.


Antibiotics are used to treat urinary tract infections (UTI). The best antibiotic depends upon the child’s age, the germ that caused the UTI, and the resistance that germs have. Most children who are older than two months are given an antibiotic by mouth, in a liquid or chewable tablet.

If the child is less than two months old, or if the child is vomiting and unable to take medicine by mouth, it may be necessary for the child to be admitted to the hospital for treatment with intravenous (IV) antibiotics.

Antibiotics are usually prescribed for a total of 5 to 10 days. In all cases, it is important for the child to take each dose of the antibiotic on time and to finish all of the medicine.

Response to treatment

Your child should begin to feel better within 24 to 48 hours of starting antibiotics. If your child does not get better or worsens, he or she should be seen again by a doctor or nurse. Most children who have a UTI have no long-term damage to the urinary tract from the infection. It is not necessary to have another urine test after a child has finished antibiotic treatment, as long as the UTI symptoms have resolved.


About 8 to 30 percent (1 in 5 to 10) of children who have a urinary tract infection (UTI) develop another UTI. This usually happens within the first six months after the first infection and is more common in girls.

Treatment of constipation and bladder problems will also help prevent future UTIs.

Preventive antibiotics

A low daily dose of an antibiotic may be recommended if your child gets frequent UTIs. This treatment is usually continued for 6 to 12 months.


If your child has any of the following, make an appointment with his or her doctor or nurse:

  • Fever – Fever (temperature higher than 100.4ºF or 38ºC) may be the only symptom of urinary tract infection in infants and young children.
  • Pain or burning with urination or frequent urination.
  • Back or abdominal pain.


Reference : https://www.uptodate.com/contents/urinary-tract-infections-in-children-beyond-the-basics?source=see_link