Urinary tract infection (UTI)
What is the urinary tract?
The kidneys filter blood to produce urine. Urine travels from the kidneys down the ureters and into the urinary bladder. The urine is stored in the bladder until urination occurs. The tube through which 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 or 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 signs and symptoms of urinary tract infection?
The signs and symptoms of urinary tract infections in children depend on the child’s age.
- Vomiting and diarrhea
- Poor feeding
- Failure to gain weight
Since these are generalized symptoms in most infants, the possibility of urinary tract infections may be overlooked.
- Burning with urination
- Lower abdominal pain
- Frequent or urgent urination
- Wetting episodes
- Side or back pain
As the child reached toddler age more classic symptoms appear, such as fever. It becomes easier to recognize urinary tract infections as the child becomes verbal and is toilet trained. Sometimes these symptoms result from other causes of urethral irritation such as bubble baths, poor hygiene, or constipation. Regardless of age, bladder infection (cystitis) is not usually associated with fever and generally does not produce and long-term damage to the bladder or kidneys. However, kidney infection (pyelonephritis) 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 you tell if my child has a urinary tract infection?
The doctor will first look at your child’s urine with a microscope (urinalysis). To be certain that there is an infection he will also do a urine culture. Your doctor will have the results of the urine culture after 24 hours. If infection is present, an additional 24 hours is usually necessary to find out which antibiotic will kill all of the bacteria. The method of urine collection will affect the accuracy of the urine culture.
It is important to:
- Wash the skin around the urethra with the cleansing pad to get rid of the bacteria on the skin’s surface.
- Keep the urine sample cold by placing it in the refrigerator at home and packing it in ice while traveling to the doctor’s office.
In small children, a urine sample is usually collected by placing a special bag over the genital area. Because bacteria from the skin may contaminate these samples, it may sometimes be necessary to pass a small plastic tube through the urethra into the bladder (bladder catheterization) to obtain a clean specimen.
When should my child be evaluated for urinary tract infection?
Children who have a culture proven urinary tract infection should have an x-ray evaluation. 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 or more urinary tract infections before having 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?
- Bladder X-ray (cystogram). A small tube is inserted into the urethra and a fluid (contrast media or isotope) flows into the bladder. X-ray pictures are taken while your child is awake. Your child will feel some discomfort but will not need medication for pain. Vesicourecteral reflux, or a 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 that might be in the bladder to reach the kidney. This can cause a kidney infection and kidney damage.
- Kidney sonogram (ultrasound). This test is done to outline the kidneys and ureters so that a blockage or urinary tract defect can be found. The test does not require radiation and is painless. If a blockage is found, surgery is usually required.
- Kidney X-ray (IVP). This test may be done if anatomy is not clearly shown on a sonogram of if certain abnormalities are suspected.
Treatment of a urinary tract infection
- All children with urinary tract infection are treated with a safe and well-tolerated antibiotic that the urine culture shows will be effective. Children with a bladder infection can usually be treated with a short course (5-7 days). Children with a kidney infection should be treated for 10-14 days. Often a sick child with a kidney infection will require hospitalization for intravenous antibiotics until the fever disappears and the urine culture results are known.
- Another urine culture will be done while your child is taking the antibiotic or when the medication is finished to make sure the infection is gone.
- If the child has never been evaluated, the antibiotics should be continued until the appropriate X-rays are done.
- Children with urinary infections may have bad voiding habits. These children are often helped by establishing a schedule and completely emptying their bladder every 3-4 hours. This problem usually disappears as the child enters puberty and, if no kidney damage was present at the time of initial evaluation, these children are not at greater risk for serious problems in the future.
- Stretching the urethra (urethra dilation) is rarely indicated. In the past it was assumed that many girls who got urinary tract infections had narrower or tight urethras. Now we know that the size of the urethra is no different between those girls who have infections and those who do not.
- Treatment for children who are found to have vesicoureteral reflux will vary according to the child’s age, number of urinary tract infections and X-ray findings. Your doctor will discuss this further with you.
- Kidney (renal) scans. This test may be done if the above tests are abnormal. It is used to better demonstrate the actual function and drainage of the kidneys. A kidney scan can also show if there is kidney damage and scarring.