Urinary Tract Infections

Urinary tract infections are a serious health problem affecting millions of people each year. Infections of the urinary tract are the second most common type of infection in the body. In United States, urinary tract infections (UTIs) account for about 8.3 million doctor visits each year. Women are especially prone to UTIs for reasons that are not yet well understood. One woman in five develops a UTI during her lifetime. UTIs in men are not as common as in Women but can be very serious when they do occur.

What are the causes of UTI?

Normally, urine is sterile. It is usually free of bacteria, viruses, and fungi but does contain fluids, salts, and waste products. An infection occurs when tiny organisms, usually bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply. The urethra is the tube that carries urine from the bladder to outside the body. Most infections arise from one type of bacteria, Escherichia coli (E. coli), which normally lives in the colon.

Who is at risk?

Some people are more prone to getting a UTI than others. Any abnormality of the urinary tract that obstructs the flow of urine (a kidney stone or congenital abnormalities, for example) sets the stage for an infection. An enlarged prostate gland also can slow the flow of urine, thus raising the risk of infection.

The use of catheters, or tubes, placed in the urethra and bladder in a person who cannot void or who is unconscious or critically ill is increasing risk of UTIs. People with diabetes have a higher risk of a UTI because of changes in the immune system. Any other disorder that suppresses the immune system raises the risk of a urinary infection.

In adult Women, the rate of UTIs gradually increases with age. Scientists are not sure why Women have more urinary infections than men. One factor may be that

A woman’s urethra is short, allowing bacteria quick access to the bladder. Also, a woman’s urethral opening is near sources of bacteria from the anus and vagina.

For many Women, sexual intercourse seems to trigger an infection, although the reasons for this linkage are unclear.

What are the symptoms of UTI?

Not everyone with a UTI has symptoms, but most people get at least some symptoms. These may include a frequent urge to urinate and a painful, burning feeling in the area of the bladder or urethra during urination. The urine itself may look milky or cloudy, even reddish if blood is present. Normally, a UTI does not cause fever if it is in the bladder or urethra. A fever may mean that the infection has reached the kidneys. Other symptoms of a kidney infection include pain in the back or side below the ribs, nausea, or vomiting. In older people, sometimes there is no specific symptom when they are suffering from UTIs. Mental changes or confusion often are the only signs of urinary tract infections.

How is UTI diagnosed?

To find out whether someone has a UTI, besides asking for those symptoms above, the doctor will test a sample of urine for pus and bacteria. The patient will be asked to give a "clean catch" urine sample by washing the genital area and collecting a "midstream" sample of urine in a sterile container. This method of collecting urine helps prevent bacteria around the genital area from getting into the sample and confusing the test results. Usually, the sample is sent to a laboratory, although some doctors’ offices are equipped to do the testing.

In the urinalysis test, the urine is examined for white and red blood cells and bacteria. Then the bacteria are grown in a culture and tested against different antibiotics to see which drug best destroys the bacteria. This last step is called a sensitivity test.

How is UTI treated?

UTIs are treated with antibacterial drugs (antibiotics). The choice of drug and length of treatment depend on the patient’s history and the urine tests that identify the offending bacteria. The sensitivity test is especially useful in helping the doctor select the most effective drug. Often, a UTI can be cured with 1 or 2 days of treatment if the infection is not complicated by an obstruction or other disorder. Still, many doctors ask their patients to take antibiotics for a week or two to ensure that the infection has been cured. A follow-up urinalysis helps to confirm that the urinary tract is infection-free. It is important to take the full course of treatment because symptoms may disappear before the infection is fully cleared. Severely ill patients with kidney infections may be hospitalized until they can take fluids and needed drugs on their own. Kidney infections generally require several weeks of antibiotic treatment. In such cases, kidney infections rarely lead to kidney damage or kidney failure unless they go untreated.

Recurrent Infections in Women

Women who have had three UTIs are likely to continue having them. Four out of five such Women get another within 18 months of the last UTI. Many Women have them even more often. A woman who has frequent recurrences (three or more a year) can ask her doctor about one of the following treatment options:

• Take low doses of an antibiotic such as TMP/SMZ or nitrofurantoin daily for 6 months or longer. If taken at bedtime, the drug remains in the bladder longer and may be more effective.
• Take a single dose of an antibiotic after sexual intercourse.
• Take a short course (1 or 2 days) of antibiotics when symptoms appear.

Dipsticks that change color when an infection is present are now available without a prescription. The strips detect nitrite, which is formed when bacteria change nitrate in the urine to nitrite. The test can detect about 90 percent of UTIs when used with the first morning urine specimen and may be useful for Women who have recurrent infections.

Doctors suggest some additional steps that a woman can take on her own to avoid an infection:

• Drink plenty of water every day.
• Urinate when you feel the need; don’t resist the urge to urinate.
• Wipe from front to back to prevent bacteria around the anus from entering the vagina or urethra.
• Take showers instead of tub baths.
• Cleanse the genital area before sexual intercourse.
• Avoid using feminine hygiene sprays and scented douches, which may irritate the urethra.
• Some doctors suggest drinking cranberry juice.

Infections in Pregnancy

Pregnant Women seem no more prone to UTIs than other Women. However, when a UTI does occur in a pregnant woman, it is more likely to travel to the kidneys. According to some reports, about 2 to 4 percent of pregnant Women develop a urinary infection. Scientists think that hormonal changes and shifts in the position of the urinary tract during pregnancy make it easier for bacteria to travel up the ureters to the kidneys. For this reason, many doctors recommend periodic testing of urine during pregnancy.