According to the National Institutes of Health, approximately 8.3 million doctor visits a year are for urinary tract infections, the second most common type of infection. About 20 percent of all women will develop a urinary tract infection over their lifetime. Any part of the urinary system can become infected, including the kidneys, ureters, bladder and urethra. Normally urine is sterile, free of bacteria or any other type of organism. Urinary tract infections, or UTIs, most commonly are caused by bacteria normally residing in the digestive tract that invade the urinary tract and multiply.
Types
Infections of the urethra, or urethritis, occur most commonly when bacteria from the anus spread to the urethra. Cystitis, a bladder infection, also is most frequently caused by the same mechanism. Urethritis and cystitis are the most common urinary tract infections and occur mainly in women, not only because of a woman's short urethra, but also because of the close proximity of the anus to the urethra. Untreated urethral or bladder infections can lead to pyelonephritis, an infection of the kidney, which may result in major complications such as kidney failure or overwhelming infection in the blood.
Causes
Bacteria are the usual organisms that infect the urinary tract, usually Escherichia coli or Staphylococcus saprophyticus. Two microorganisms, Chlamydia and Mycoplasma, that cause UTIs can be sexually transmitted, requiring treatment of both partners. Less frequently, urinary tract infections are caused by fungi or viruses, usually seen in immunocompromised patients.
Risk Factors
MayoClinic.com lists several risk factors for developing a urinary tract infection. These include female gender, sexual activity, use of a diaphragm for birth control, menopause, underlying anatomical abnormalities of the urinary tract, a weak immune system and the use of a bladder catheter. Elderly women were once considered to have a particularly high risk of urinary tract infections with complications; however, a 2009 study reported by Grover and colleagues in the "Journal of the American Board of Family Medicine" found that woman older than 65 who were otherwise healthy did have not have a greater risk of complicated urinary tract infections compared to younger women.
Identification
Symptoms of a urinary tract infection include a strong urge to urinate, burning with urination, increased urinary frequency, foul-smelling urine and red-tinged or cloudy urine. Pelvic pain in women and rectal pain in men may also be indicators of a UTI. The presence of fever, chills, nausea and vomiting may indicate a kidney infection. The diagnosis of a urinary infection is confirmed by an analysis of the urine. Sometimes special x-rays, ultrasound or scoping the urinary system may be utilized to look for anatomical abnormalities.
Treatment
Urinary tract infections caused by bacteria are treated with antibacterial drugs. If the specific infecting bacteria is known, antibiotic therapy can be targeted against those bacteria. More often, patients with urinary tract infections are treated based on the most likely causative bacteria. The University of Maryland Medical Center reports that trimethoprim-sulfamethoxazole has been traditionally the first-choice antibiotic; however, many bacteria have become resistant to this drug and quinolone antibiotics are increasingly used. Other antibiotics used include amoxicillin, nitrofurantoin and ampicillin. Although most urinary tract infections can be treated with oral antibiotics, serious kidney infections usually require hospitalization, vigorous hydration and intravenous antibiotics. Fungal and viral urinary tract infections are treated with anti-fungal and anti-viral drugs, respectively. Symptoms of a urinary tract infection can be alleviated with the use of drugs to decrease the pain and burning--such as phenazopyridine drugs--or methenamine to decrease infection-related bladder spasms.
Prevention/Solution
Several measures, particularly in women, can be taken to prevent urinary tract infections. These include wiping front to back, taking showers instead of baths, cleansing the genital area before sexual intercourse and urinating immediately after, as well as avoiding feminine hygiene products. Women with recurrent urinary tract infections who use a diaphragm for birth control may want to consider an alternative form of preventing an unwanted pregnancy. Some doctors advocate the use of cranberry juice, although this has not been confirmed to be helpful in any well-controlled clinical trial.
References
- National Kidney and Urologic Diseases Information Clearinghouse: Urinary Tract Infections in Adults
- MayoClinic.com: Urinary tract infection
- "Journal of the American Board of Family Medicine": Urinary Tract Infection in Women Over the Age of 65
- University of Maryland Medical Center: Urinary tract infections - Medications
