FAQ: Urinary Tract Infection in Children

Linda M. D. Shortliffe, M.D.

What Is A Urinary Infection? The urinary tract makes and stores urine, one of the body's liquid waste products. The kidneys produce about 1 1/2 to 2 quarts per day in an adult and less in children depending upon their age. The kidney removes waste and water from the blood. The urine travels from the kidneys down two narrow tubes, the ureters. It is then stored in a balloon-like container called the bladder.

In a child the bladder can hold about an ounce to ounce and a half of urine per year of the child's age (example a 4 year old child may hold about 4-6 ounces, a little less than a cup in the bladder). When the bladder empties urine is carried out of the body through the urethra, a tube at thebottom of the bladder. The opening of the urethra is at the end of the penis in men and in front of the vagina in women.

Normal urine contains no bacteria (germs), but bacteria do cover your skin and are present in large numbers in the rectal area and in your bowel movements. Bacteria may, at times, get into the urinary tract (and the urine) and may travel up the urethra into the bladder. When this happens, the bacteria cause infection and inflammation of the bladder. In other words, they multiply, causing redness, swelling, and pain. If the bacteria remain in the bladder this is called cystitis. If the bacteria travel upward from the bladder through the ureters and reach the kidneys, a kidney infection known as pyelonephritis develops. Kidney infections are much more serious than bladder infections.

What Are The Signs Of A Urinary Tract Infection In Your Child?

When there is a urinary tract infection, the lining of the bladder, urethra, ureters, and kidneys become red and irritated just as the inside of your nose or throat does when you have a cold. If your child is an infant or is only a few years old the signs of a urinary tract infection may not be very clear since the child is too young to tell you just how he or she feels. Your child may have a high fever, be irritable, and not eat. On the other hand, sometimes a child may only have a low-grade fever or loose bowel movements or just not seem healthy. You may notice that the diaper urine has an unpleasant smell. If your child has a high temperature and appears sick without signs of a runny nose or other obvious source for his discomfort for more than a day, they may need to see a doctor. If a kidney infection is not treated promptly, the bacteria may spread to the blood-stream and cause a life-threatening infection.

In an older child the bladder irritation may cause pain the the abdominal and pelvic area and may make your child empty their bladder often. They may complain of flank or low back pain. Your child may cry when he or she urinates or complain that it hurts to urinate and produce only a few drops of urine. It may be hard for the child to control urine and they may suddenly begin leaking urine into their clothing or bed without any other signs. The urine may smell unpleasant or may look cloudy.

How Do You Find Out Whether Your Child Has A Urinary Tract Infection?

Only by consulting a doctor can you find out for certain whether your child has a urinary tract infection. If you think that such an infection might be present, check with your child's doctor.

Your child's doctor will ask you to collect some of your child's urine, so it can be examined. The way that the urine is collected may depend on how old your child is. The doctor may stick a plastic bag to your child's bottom if your child is not yet toilet trained or in an older child ask you to help collect a specimen while your child empties their bladder. Since it is important that the urine collected be free from surrounding skin and rectal bacteria, it is sometimes necessary to pass a small tube into the urethra or a needle into the low abdomen and into the bladder directly to be certain that the urine collected is a good sample.

A sample of the urine is then examined under a microscope. If an infection is present, your doctor may be able to see bacteria and pus. The doctor may also perform a urine culture, a process in which bacteria from infected urine are grown in a laboratory. The germs can then be identified and tested to see which drugs will provide the most effective treatment. If often takes a day or more, however, to complete this testing.

How Are These Infections Treated?

Urinary tract infections are treated with antibiotics (infection-fighting drugs). Your doctor will choose a drug that treats the bacteria most likely to be causing your child's infection. Once the test results are finished, however, your doctor may switch you to another antibiotic, one that is more effective against the particular bacteria found in your urine.

The way the antibiotic is given to your child and the number of days that it must be taken depend, in part, on the type of infection your child has and how severe it is. If your child is very sick or not able to take fluids, the antibiotic may need to be given intravenously (injected directly into the bloodstream) while your child is in the hospital or by shots; otherwise oral medicine may be given. Your child will usually have to take the medicine for at least 3 to 5 days and possibly for as long as several weeks. The daily treatment schedule your child's doctor recommends depends on the specific drug prescribed: it may call for a single dose each day or up to four daily doses. In some cases you will be asked to give your child medicine until further tests are finished.

After a few doses of the antibiotic, your child may appear much improved, but often it may be several days before all symptoms are gone. In any case, it is important to take the medicines as prescribed by your doctor and not to stop them simply because the symptoms have gone away. Unless urinary tract infections are fully treated, they may return.

You should have your child drink fluids when they wish, but it is not necessary to force them to drink large amounds of fluid. It is important that your child can take the liquid he or she needs and if for some reason is unable to take it, you need to tell your child's doctor.

Why Did Your Child Get A Urinary Tract Infection?

In some children a urinary tract infection may be the sign of an abnormal urinary tract. For this reason when a child is found to have a urinary tract infection, it may be recommended that they get additional tests and x-rays. In other children, however, children develop urinary tract infections because they are prone to such infections the way other people children are prone to gettiing coughs, colds, or ear infections. In other instances a child may get an infection with a bacteria that has a special capability of causing urinary tract infections.

What Tests May Be Needed After The Infection Is Gone?

Once the infection has cleared, your child's doctor may recommend additional tests. The tests are performed to assure that there are no abnormalities in the urinary tract that might result in kidney damage from urinary tract infections. The kinds of tests ordered will depend on your child and the kind of urinary infection they have. Unfortunately none of the tests alone can tell everything about the urinary tract that might be important to know after having a urinary tract infection, so often more than one test is needed. The tests that might be needed are:

Kidney and/or bladder ultrasound: a test that examines the kidney and bladder using sound waves. This test shows shadows of the kidney and bladder that may show some kinds of abnormalities, but cannot show all important urinary tract abnormalities. It also cannot tell how well a kidney works.

Voiding cystourethrogram (VCUG): a test in which a small tube (catheter) is placed into the urethra. A kind of dye that can be seen on x-rays in then placed into the bladder through the tube until your child empties the bladder. This important test can show abnormalities of the inside of the urethra, bladder, and if the flow of urine is normal when the bladder empties.

Intravenous pyelogram: a test in which a kind of dyethat can be seen on x-rays is given intravenously (injected into the bloodstream). The dye goes to the kidneys and bladder to show the urinary tract and how the are connected and empty.

Nuclear scans: there are many kinds of nuclear scans of the bladder and kidneys, and they each give different kinds of information about the kidneys and bladder. These scans use liquids that have different radioactive materials in them. From these tests a doctor can sometimes tell how well the kidneys work, the shape of the kidneys, and if the urine empties from the bladder in a normal way. Although the liquids that are used may have special radioactive materials in them, this does not mean they give more radiation than other kinds of x-rays. Sometimes they give your child much less radiation exposure.

Do Urinary Tract Infections Have Long-Term Effects?

Young children have the greatest risk for kidney damage from urinary tract infections especially if they have some unknown urinary tract abnormality. Such damage may lead to kidney scars, poor kidney growth, poor kidney function, high blood pressure, and other problems. For this reason, it is important that children with urinary tract infections receive prompt treatment and careful evaluations.

What Kinds Of Abnormalities Of The Urinary Tract Could A Child Have If They Have A Urinary Infection?

Many children that get urinary infections have normal kidneys and bladders, but the children that have abnormalties should be detected as early as possible in life to try to protect their kidneys against damage. Some of the abnormalities that could occur are:

Vesicoureteral reflux: the urine usually flows from the kidney down the ureters to the bladder in one direction. With reflux, the urine may also flow backwards from the bladder up the ureters to the kidneys. This abnormality is commonly found in children with urinary infections.

Urinary Obstruction: blockages to urinary flow may occur at many sites in the urinary tract. They usually occur if the ureter or urethra is too narrow or is blocked at some point and the urinary flow is blocked from leaving the body. Occasionally the ureter (tube emtying urine from the kidneys) may be connected into the wrong place and may also block urine from leaving the body in a normal way.