Augusta Healthcare for Women
Urinary tract infections (UTIs) are bacterial infections of the organs through which urine is excreted, including the bladder and kidneys. Infections of the bladder are formally called "cystitis" and infections of the kidneys are called "pyelonephritis".
The kidneys filter and remove waste and water from the blood to produce urine. They get rid of about 1-1/2 to 2 quarts of urine per day in an adult and less in a child, depending on the child's age.
The urine travels from the kidneys down two narrow tubes called the ureters. The urine is then stored in a balloon-like organ called the bladder. In a child, the bladder can hold about 1 to 1-1/2 ounces of urine for each year of the child's age. So, the bladder of a 4-year-old child may hold about 4 to 6 ounces (less than 1 cup); an 8-year-old can hold 8 to 12 ounces.
When the bladder empties, a muscle called the sphincter relaxes and urine flows out of the body through the urethra, a tube at the bottom of the bladder. The opening of the urethra is at the end of the penis in boys and in front of the vagina in girls.
Normal urine contains no bacteria (germs). Bacteria may, at times, get into the urinary tract and the urine from the skin around the rectum and genitals by traveling up the urethra into the bladder. When this happens, the bacteria can infect and inflame the bladder and cause swelling and pain in the lower abdomen and side. This bladder infection is called cystitis.
If the bacteria travel up through the ureters to the kidneys, a kidney infection can develop. The infection is usually accompanied by pain and fever. Kidney infections are much more serious than bladder infections.
In some children a urinary tract infection may be a sign of an abnormal urinary tract that may be prone to repeated problems. For this reason, when a child has a urinary infection, additional tests are often recommended. In other cases, children develop urinary tract infections because they are prone to such infections, just as other children are prone to getting coughs, colds, or ear infections. Or a child may happen to be infected by a type of bacteria with a special ability to cause urinary tract infections.
Children who frequently delay a trip to the bathroom are more likely to develop UTIs. Regular urination helps keep the urinary tract sterile by flushing away bacteria. Holding in urine allows bacteria to grow. Keeping the sphincter muscle tight for a long time also makes it more difficult to relax that muscle when it is time to urinate. As a result, the child’s bladder may not empty completely. This dysfunctional voiding can set the stage for a urinary infection.
A urinary tract infection causes irritation of the lining of the bladder, urethra, ureters, and kidneys, just like the inside of the nose or the throat becomes irritated with a cold. If your child is an infant or only a few years old, the signs of a urinary tract infection may not be clear, since children that young cannot tell you exactly how they feel. Your child may have a high fever, be irritable, or not eat.
On the other hand, sometimes a child may have only a low-grade fever, experience nausea and vomiting, or just not seem healthy. The diaper urine may have an unusual smell. If your child has a high temperature and appears sick for more than a day without signs of a runny nose or other obvious cause for discomfort, he or she may need to be checked for a bladder infection.
An older child with bladder irritation may complain of pain in the abdomen and pelvic area. Your child may urinate often. If the kidney is infected, your child may complain of pain under the side of the rib cage, called the flank, or low back pain. Crying or complaining that it hurts to urinate and producing only a few drops of urine at a time are other signs of urinary tract infection. Your child may have difficulty controlling the urine and may leak urine into clothing or bedsheets. The urine may smell unusual or look cloudy or red.
Only by consulting a health care provider can you find out for certain whether your child has a urinary tract infection.
Some of your child's urine will be collected and examined. The way urine is collected depends on your child’s age. If the child is not yet toilet trained, the health care provider may place a plastic collection bag over your child's genital area. It will be sealed to the skin with an adhesive strip. An older child may be asked to urinate into a container. The sample needs to come as directly into the container as possible to avoid picking up bacteria from the skin or rectal area. A doctor or nurse may need to pass a small tube into the urethra. Urine will drain directly from the bladder into a clean container through this tube, called a catheter. Sometimes the best way to get the urine is by placing a needle directly into the bladder through the skin of the lower abdomen. Getting urine through the tube or needle will ensure that the urine collected is pure.
Some of the urine will be examined under a microscope. If an infection is present, bacteria and sometimes pus will be found in the urine. If the bacteria from the sample are hard to see, the health care provider may place the sample in a tube or dish with a substance that encourages any bacteria present to grow. Once the germs have multiplied, they can then be identified and tested to see which medications will provide the most effective treatment. The process of growing bacteria in the laboratory is known as performing a culture and often takes a day or more to complete.
The reliability of the culture depends on how long the urine stands before the culture is started. If you collect your child's urine at home, refrigerate it as soon as it is collected and carry the container to the health care provider or lab in a plastic bag filled with ice.
Urinary tract infections are treated with bacteria-fighting drugs called antibiotics. While a urine sample is being examined, the health care provider may begin treatment with a drug that treats the bacteria most likely to be causing the infection. Once culture results are known, the health care provider may decide to switch your child to another antibiotic.
The way the antibiotic is given and the number of days that it must be taken depend in part on the type of infection and how severe it is. When a child is sick or not able to drink fluids, the antibiotic may need to be put directly into the bloodstream through a vein in the arm or hand. Otherwise, the medicine (liquid or pills) may be given by mouth or by shots. The medicine is given for at least 3 to 5 days and possibly for as long as several weeks. The daily treatment schedule recommended depends on the specific drug prescribed: The schedule may call for a single dose each day or up to four doses each day. In some cases, your child will need to take the medicine until further tests are finished.
After a few doses of the antibiotic, your child may appear much better, but often several days may pass before all symptoms are gone. In any case, your child should take the medicine for as long as the doctor recommends. Do not stop medications because the symptoms have gone away. Infections may return, and germs can resist future treatment if the drug is stopped too soon.
Children should drink fluids when they wish. Make sure your child drinks what he or she needs, but do not force your child to drink large amounts of fluid. The health care provider needs to know if the child is not interested in drinking.
Once the infection has cleared, additional tests may be recommended to check for abnormalities in the urinary tract. Repeated infections in abnormal urinary tracts may cause kidney damage. The kinds of tests ordered will depend on your child and the type of urinary infection. Because no single test can tell everything about the urinary tract that might be important, more than one of the following tests may be needed:
Many children who get urinary tract infections have normal kidneys and bladders. But if a child has an abnormality, it should be detected as early as possible to protect the kidneys against damage. Abnormalities that could occur include the following:
Young children are at the greatest risk for kidney damage from urinary tract infections, especially if they have some unknown urinary tract abnormality. Such damage includes 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 evaluation.
If your child has a normal urinary tract, you can help him or her avoid UTIs by encouraging regular trips to the bathroom. Make sure your child gets enough to drink if infrequent voiding is a problem. Teach your child proper cleaning techniques after using the bathroom to keep bacteria from entering the urinary tract.
Some abnormalities in the urinary tract correct themselves as the child grows, but some defects may require surgical correction.
Reference: The National Institute of Diabetes and Digestive and Kidney Diseases