Urinary Tract Infection

What causes a urine infection?

Urine infections occur when microorganisms, usually bacteria, enter the urinary tract and remain long enough to cause inflammation and other problems. It is thought that almost all urine infections are caused by bacteria entering the urine channel (the urethra [you-ree-thrah]) and moving up into the bladder. Sometimes urine infections can move up the tubes that drain the kidneys to the bladder (the ureters [you-ruh-ters]) to cause a kidney infection.

How common are urine infections?
Urine infections occur in about 1/20 school age girls, but less than 1/100 school age boys. Urine infections can occur in infants and they are more common in infant boys than in infant girls.

How would I know if my child has a urine infection?
The symptoms usually associated with a urine infection depend on the age of the child. Infants and very young children may have fever, fussiness, decreased activity, decreased appetite or just a general change in behavior. Of course, these same symptoms could be caused by an ear infection, a viral illness or other diseases. That’s why an infant with any of the above symptoms should be tested to see if a urine infection or any other type of infection is present. Older children may have pain with urination, loss of urine control (wetting), pain in the lower abdomen, fever or pain in the side of the back. Sometimes a urine infection will cause blood to appear in the urine. Sometimes children with urine infection pass urine that smells bad.

What should I do if I think my child has a urine infection?
You should call your child’s doctor to have your child examined and to have his/her urine tested.

How are urine infections treated?
Most urine infections can be treated at home with antibiotics taken by mouth. If your child’s doctor prescribes antibiotics it is very important that your child takes the antibiotics exactly as instructed. That is the best way to make sure the infection is completely treated. Occasionally, a child with a severe urine infection may need to be admitted to the hospital for antibiotics given through an intravenous line.

Are urine infections dangerous?
That depends on how severe the infection is an where it is located in the urinary tract. An single infection that is present only in the bladder may cause pain and difficulty controlling the urine, but it would rarely cause any long lasting damage. A severe kidney infection, however, may cause enough inflammation to cause part of the kidney to be scarred. Children who have suffered many kidney infections can suffer enough kidney damage to cause high blood pressure and even loss of kidney function. Fortunately, that rarely occurs.

Will the infection come back?
About 1/3 of children who have had a urine infection will develop another urine infection. That is why it is important to have your child evaluated by your doctor.

Why would a urine infection come back?
Several factors can make it easier for bacteria to enter the urinary tract and cause an infection. Irritation at or near the opening of the urine channel can interfere with the body’s natural defense system and allow bacteria to move into the bladder. If a child doesn’t empty his/her bladder completely at urination, infection is more likely to return. A child who empties his/her bladder infrequently may be at increased risk for a urine infection. Constipation can interfere with the normal function of the bladder. A partial blockage of the urine channel, the kidney or the ureters can also make infection more likely. Normally urine flows in one direction in the body: from the kidneys, down the ureters to the bladder and out of the bladder through the urine channel. About 1/3 of children who have urine infections are found to have backwards leakage of urine from the bladder up the ureter to the kidney. This is called reflux.

How can I protect my child from urine infections?
If your child has had a urine infection your doctor may recommend an evaluation to see if something can be done to decrease the risk of another infection. Your doctor may order an ultrasound exam of the kidneys and the bladder. This is done to detect any enlargement of the urine drainage system. Your doctor may also evaluate your child’s urination pattern (how frequently your child urinates and how much comes out each time). Your doctor may order a test to look for reflux (see above). This test is called a voiding cystourethrogram or VCUG and it is the only test that can detect reflux.

In general, making sure your child drinks plenty of fluids (there’s nothing better than water), has good personal cleanliness and urinates regularly are important ways to keep your child safe from urine infections. If your child has had urine infection, it is very important to follow your doctor’s plan for evaluating your child’s risk for getting another infection.