Urinary Tract Infections in Adults Urinary tract infections are a serious health problem affecting millions of people each year. In 1997, urinary tract infections (UTIs) accounted for about 8.3 million doctor visits. One woman in five develops a UTI during her lifetime. UTIs in men are not so common, but they can be very serious when they do occur. The key element in the urinary system is a pair of brown organs located below the ribs called as the kidneys. The kidneys remove excess liquid and wastes from the blood in the form of urine, keep a stable balance of salts and other substances in the blood. Narrow tubes called ureters carry urine from the kidneys to the bladder, a triangle-shaped chamber in the lower abdomen. Urine is stored in the bladder and emptied through the urethra. The average adult passes about a quart and a half of urine each day. The amount of urine varies, depending on the fluids and foods a person consumes. The volume formed at night is about half that formed in the daytime. Causes Normal urine is sterile. It contains fluids, salts, and waste products, but it is free of bacteria, viruses, and fungi. An infection occurs when microorganisms, usually bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply. Most infections arise from one type of bacteria, Escherichia coli (E. coli), which normally lives in the colon. In most cases, bacteria first begin growing in the urethra. An infection limited to the urethra is called urethritis. From there bacteria often move on to the bladder, causing a bladder infection (cystitis). If the infection is not treated promptly, bacteria may then go up the ureters to infect the kidneys (pyelonephritis). Microorganisms called Chlamydia and Mycoplasma may also cause UTIs, but these infections tend to remain limited to the urethra. The urinary system is structured in a way that helps ward off infection. The ureters and bladder normally prevent urine from backing up toward the kidneys, and the flow of urine from the bladder helps wash bacteria out of the body. In both sexes, immune defenses also prevent infection. But despite these safeguards, infections still occur. Risk factor 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, for example) sets the stage for an infection. A common source of infection is catheters, or tubes, placed in the bladder. People with diabetes have a higher risk of a UTI because of changes in the immune system. Any disorder that suppresses the immune system raises the risk of a UTI. UTIs may occur in infants who are born with abnormalities of the urinary tract. In women, though, 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. Many women suffer from frequent UTIs. Nearly 20 percent of women who have a UTI will have another. Usually, the latest infection stems from a strain or type of bacteria that is different from the infection before it, indicating a separate infection. Research funded by the National Institutes of Health (NIH) is being undertaken Symptoms Not everyone with a UTI has symptoms, but most people get at least some. These may include a frequent urge to urinate and a painful, burning feeling in the area of the bladder or urethra during urination. It is not unusual to feel bad all over-tired, shaky, washed out-and to feel pain even when not urinating. It is common for a person with a urinary infection to complain that, despite the urge to urinate, only a small amount of urine is passed. The urine itself may look milky or cloudy, even reddish if blood is present. 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. Diagnosis To find out whether you have a UTI, your doctor will test a sample of urine for pus and bacteria. Usually, the sample is sent to a laboratory, although some doctors are equipped to do the testing. In the urine analysis test, the urine is examined for white and red blood cells and bacteria. The bacteria are grown and tested against different antibiotics to see which drug best destroys the bacteria. This last step is called a sensitivity test. When an infection does not clear up with treatment and is traced to the same strain of bacteria, the doctor will order a number of tests that makes images of the urinary tract. Treatment UTIs are treated with antibacterial drugs. 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. The drugs most often used to treat routine, uncomplicated UTIs are trimethoprim, trimethoprim / sulfamethoxazole, amoxicillin, nitrofurantoin, and ampicillin. A class of drugs called quinolones includes four drugs approved in recent years for treating UTI. These drugs include ofloxacin, norfloxacin, ciprofloxacin, and trovafloxin. Often, a UTI can be cured with 1 or 2 days of treatment if the infection is not complicated by an obstruction or nervous system disorder. Still, many doctors ask their patients to take antibiotics for a week or two to ensure that the infection has been cured. Single-dose treatment is not recommended for some groups of patients, for example, those who have delayed treatment or have signs of a kidney infection, patients with diabetes or structural abnormalities, or men who have prostate infections. Patients also need longer treatment with infections caused by Mycoplasma or Chlamydia, which are usually treated with tetracycline, trimethoprim/sulfamethoxazole, or doxycycline. A followup 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. Researchers at the University of Washington found that 2-week therapy with TMP/SMZ was as effective as 6 weeks of treatment with the same drug in women with kidney infections that did not involve an obstruction or nervous system disorder. In such cases, kidney infections rarely lead to kidney damage or kidney failure unless they go untreated. Various drugs are available to relieve the pain of a UTI. A heating pad may also help. Most doctors suggest that drinking plenty of water helps cleanse the urinary tract of bacteria. During treatment, it is best to avoid coffee, alcohol, and spicy foods. And one of the best things a smoker can do for his or her bladder is to quit smoking. Smoking is the major known cause of bladder cancer. Vaccination In the future, scientists may develop a vaccine that can prevent UTIs from coming back. Researchers in different studies have found that children and women who tend to get UTIs repeatedly are likely to lack proteins called immunoglobulins, which fight infection. Children and women who do not get UTIs are more likely to have normal levels of immunoglobulins in their genital and urinary tracts. Early tests indicate that a vaccine helps patients build up their own natural infection-fighting powers. The dead bacteria in the vaccine do not spread like an infection; instead, they prompt the body to produce antibodies that can later fight against live organisms. Researchers are testing injected and oral vaccines to see which works best. Another method being considered for women is to apply the vaccine directly as a suppository in the vagina.