As many as 8 percent of girls and 2 percent of boys will
develop a urinary tract infection. Furthermore, young children have a greater
risk of kidney damage linked to urinary tract infection than older children or
adults. The information below should help you recognize a urinary tract
infection in children before it causes serious damage.
What
happens under normal conditions?
The urinary tract controls the outflow of urine, one of
the body's liquid waste products. The kidneys produce about 1and 1/2 to two
quarts a day in an adult, and less in children, depending on their age. Urine
travels from the kidneys down tubes, the ureters, into a balloon-like container called the bladder. In
children, the bladder can hold 1 to 1 and 1/2 ounces of urine for every year of
age (e.g., four to six ounces, or a little less than a cup, in a
four-year-old). When the bladder empties, it pushes the urine out of the body
through a tube at the bottom of the bladder called the urethra. The opening of the
urethra is at the end of the penis in boys and in front of the vagina in girls.
In normal children, there is flow of urine only in one direction, from the
kidneys, down the ureters, into the bladder and then out the urethra. This
constant one directional flow helps prevent infections.
What
causes urinary tract infections in children?
Normal urine is sterile and contains no bacteria. However, even under normal
circumstances bacteria cover the skin and are present in large numbers in the rectal area and
within bowel movements. Bacteria may, at times, get into the urinary tract and
travel up the urethra into the bladder. When this happens, the bacteria
multiply and unless the body gets rid of the bacteria, they can cause infection
(urinary tract infection or "UTI."
There are two general types of UTIs—bladder infection
and kidney infection. When the infection involves the bladder it can cause
inflammation, swelling and pain of the bladder. This is called cystitis. If the bacteria travel
upward from the bladder through the ureters and reach and infect the kidneys, the kidney infection
is called pyelonephritis. Kidney
infections are more serious than bladder infections, and can cause kidney
damage especially in young children.
What are
the symptoms of urinary tract infections in children?
Most often when there is a urinary tract infection, the
linings of the bladder, urethra, ureters, and kidneys become red
and irritated. This usually causes painful, frequent urination and children may
pass urine with a foul odor. Many children start having urinary accidents,
and/or bloody urine. If the kidneys become infected, children often have
abdominal or back pain and fever. If your child is an infant or too young to
tell you how he or she feels, the signs are likely to be vague and unrelated to
the urinary tract. For example, your child may just have a high fever, or be
irritable and not eating, or sometimes have only a low-grade fever, loose bowel
movements or just not seem healthy. You may notice that the diaper urine
"smells bad." If your child has a high temperature and appears sick
without another obvious source for his/her discomfort (such as runny nose or
ear ache), they should see a doctor. If a kidney infection is not treated promptly,
the bacteria may spread to the bloodstream and cause a life-threatening
infection or permanent kidney damage.
Older children may complain of pain in the low stomach
area or back as well as the need to urinate frequently. 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 them to control their urine so they may have
urinary accidents or bed-wetting. They may also produce urine that smells bad
or looks cloudy.
How are
urinary tract infections diagnosed in children?
If you think your child has a urinary tract infection, call
your doctor. The only way to diagnose a urinary infection is with a urine test.
Your doctor will collect a urine sample for evaluation. The method your
physician uses will depend on your child's age. For instance, if your toddler
is not toilet-trained, your doctor may simply attach a plastic bag to their
skin to collect the sample. If your child is older, you may be asked to help
catch the specimen as your child empties his or her bladder. Since it is
critical that the collected urine be free from bacteria on the surrounding
skin, it is sometimes necessary to pass a small tube into the urethra or a needle into the low
abdomen into the bladder directly to collect a good sample.
This sample of urine is then examined under a
microscope. If an infection is present, your doctor may be able to see bacteria
and pus (white blood cells). This test takes only a few minutes. The doctor may
also perform a urine culture, a process in which bacteria from urine are grown
in a laboratory incubator to determine whether there is significant bacterial
growth. The bacteria can then be identified and tested to see which drugs will
most effectively treat the infection. There are many different kinds of
bacteria that can infect the urine and different types of bacteria may require
different types of antibiotic treatment. It takes several days to complete
urine culture testing.
How are
urinary tract infections treated in children?
Urinary
tract infections are treated with antibiotics. If your doctor thinks
your child has a urine infection, they will choose a drug that treats the
bacteria most likely to be causing the problem. Sometimes a few days later,
after the culture results
are finished, the antibiotic drug might be changed to one that is more
effective against the particular bacteria found in your child's urine. In
addition to antibiotics, you can help your child's body fight the infection by
encouraging lots of fluids and very frequent urination.
The specific antibiotic drug, way it is given and number
of days that it must be taken may depend, in part, on the type and severity of
infection. If your child is very sick and unable to take fluids, the antibiotic
may need to be given as shots (injected directly into the bloodstream or
muscle) with your child in the hospital; otherwise, oral medicine may be given.
The daily treatment schedule your child's doctor recommends will depend upon
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 or even have returned to their normal activities, but
often it may take weeks before all symptoms are gone. Even if they are
improved, it is important that your child take the antibiotic medicines as
prescribed by your doctor and not stop them because just because the symptoms
have gone away. Unless urinary tract infections are fully treated, they may
return, or your child may get another infection.
What can
be expected after treatment for urinary tract infections in children?
Once the infection has cleared, your child's doctor may
recommend additional tests, particularly if they have been treated for a kidney
infection. The tests are performed to assure that there are no abnormalities in
the urinary tract that might prevent your child's body from fighting off the
infection and to assess whether there has been any kidney damage from urinary tract infections. The
specific tests ordered will depend on your child and the kind of urinary
infection they had. Unfortunately no single test can tell everything about the
urinary tract that might be important to know after having a urinary tract
infection. For that reason several tests are usually recommended. If these
studies show a urinary tract abnormality, your doctor may want you to see a
urologist.
Additional tests may include:
Kidney
and/or bladder ultrasonography: This test gets pictures of the
kidney and bladder using sound waves. This test may show shadows that indicate
some kinds of abnormalities, like blockages, but cannot show all important
urinary tract abnormalities. It also cannot tell how well the kidney works.
Voiding
cystourethrogram (VCUG): This important test can show abnormalities of the
inside of the urethra and
bladder, and if urinary flow is normal during bladder emptying. It also tells
your doctor if urine from the bladder is backing up into the ureters (vesicoureteral reflux) and
whether it reaches the kidneys. In this test a small soft tube (catheter) is placed into the
urethra. A liquid that can be seen on X-rays is then placed into the bladder
through the tube until your child empties their bladder.
Nuclear
scans: There are different kinds of scans of the bladder and kidneys
each can be used to give different kinds of information. These scans use
liquids that have tiny amounts of various radioactive tracer 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 kidneys or bladder in a normal way. Although the liquids that
are used have radioactive materials in them, the total amount of radiation
exposure for your child is tiny.
CT scan or MRI: These are imaging tests
examine the bladder and kidneys in three dimensions. They are sometimes used
for complicated infections when the other studies are unclear and more detail
of these organs may be needed.
Frequently
asked questions:
I have
heard of urinary tract infections in adults but how did my child get one?
The normal body has natural resistance to urinary
infections. In some children a urinary tract infection may be a sign of an abnormality
that lowers this resistance. 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 some cases, the problem may not show up on x-rays. Many children
develop urinary tract infections because they do not use the restroom regularly
or do not empty their bladder completely. In addition, some children with
repeated UTIs have trouble with bladder control during the day. Similarly,
constipation is associated with urinary infections and treating this problem
can reduce the change of developing a UTI. Urologist call this condition
"dysfunctional elimination syndrome." Drinking more water and
urinating frequently are ways the body can enhance its ability to fight off
urinary infections.
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. The damage can cause scarring, poor growth and abnormal
function of the kidney as well as high blood pressure and other problems. For
those reasons, it is imperative that your child be evaluated carefully and
treated promptly.
What
kinds of abnormalities of the urinary tract could a child have if he/she has a
urinary infection?
Many children who get urinary infections have normal
kidneys and bladders, but the children who have abnormalities should be
detected as early as possible in life to try to protect their kidneys against
damage. Some of the more common abnormalities that may be present are:
Vesicoureteral
reflux: Normally urine flows from the kidney down the ureters and into the bladder. This
one-way flow is usually maintained because of a "flap-valve"
mechanism at the where the ureter joins the bladder. When vesicoureteral reflux is
present, the urine flows backwards from the bladder up the ureters to the
kidneys. This refluxing urine may carry with it bacteria that is present in the
bladder, up to the kidneys and cause a more serious kidney infection (pyelonephritis).
Urinary
Obstruction: Blockages to urinary flow may occur at many locations
in the urinary tract, and in children commonly represent birth abnormalities.
These blockages are usually caused by abnormal narrow areas in the urinary
tract that prevent normal flow of urine out of the body.
Can
urinary tract infections be prevented?
If your child, who had a urinary tract infection, has
been found to have a normal urinary tract, certain habits may be useful to prevent
future urinary infections. Frequent bladder emptying is one of the body’s best
defense mechanisms against urinary infections. Increased fluids and hence
increased urine flow will also flush the infection out of the body. Treatment
of constipation also helps. In some children who are very prone to getting
urinary infections, it may be difficult to prevent recurrent infections and low
dose preventive antibiotics are useful.
