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Urinary Tract Infection

Introduction

  • Urinary tract infection (UTI) is a common problem in the elderly.
  • An infection anywhere along the urinary tract is called a UTI.
  • In elderly, diagnosis, prevention and treatment can often be difficult because symptoms can be not typical. Also the body’s resistances to disease decrease with age.
  • Fortunately, most UTIs respond very well to treatment.

Causes

  • Germs that cause UTIs always come from the skin at or near the opening of the urethra (which channels the urine outside of the body).
  • Women are prone to UTIs because they have shorter urethra than men, thus germs have a shorter distance to travel to reach the bladder.
  • Older women are especially prone to UTIs because the drop in hormone (estrogen) level with menopause leads to thinning of the urethra’s lining and weaken its defense against infection.
  • In older men, the prostate gland grows bigger (a condition called benign prostatic hyperplasia) and compresses the urethra enough to interfere with urine outflow. The prostate gland may become infected (prostatitis), and germs can intermittently spread from the prostate into the urinary tract.
  • Among some older people, urine outflow from the bladder can be abnormal because bladder muscles contract weakly or the nerves to the bladder are damaged (neurogenic bladder).
  • Medical procedures that require insertion of devices into the urinary tract eg. use of urinary tubes (catheters) may cause UTIs.
  • Very rarely, germs from an infection elsewhere in the body pass from the blood into the kidneys, causing a kidney infection (pyelonephritis)

Type of germ

  • Escherichia coli is the bacteria most often responsible for UTIs
  • Other bacteria, such as Klebsiella, Enterobacter, Proteus, and Pseudomonas, Enterococcus and Staphylococcus also can cause urinary infections.
  • Fungi (such as Candida) and viruses are rarer causes.

Sign and Symptoms

Symptoms of UTIs

  • Painful burning sensation, need to urinate frequently, often at night (nocturia) and urgency (the feeling that you need to rush to toilet).
  • May cause an uncontrollable loss of urine (incontinence) due to the urge to urinate
  • Fever is uncommon unless the infection has spread to become an upper urinary tact infection or spread to the blood (sepsis).
  • Flank or back pain may result from an infected kidney (pyelonephritis).
  • Confusion can develop, especially if patients have high fever.
  • The urine may be foul smelling or appear cloudy or bloody.
  • Sometimes, there are no symptoms even though the bacteria is in the bladder. This is called asymptomatic bacteriuria.

Diagnosis

  • A doctor usually suspects UTIs on the basis of the symptoms alone.
  • Tests on a urine sample confirm the diagnosis.
  • A urine sample is obtained by first cleansing the skin surrounding the urethra, then urinating into a sterile container.
  • The urine is tested with strips to check for nitrites (substances released by bacteria) and leukocyte (white blood cells).
  • The urine can be sent to the laboratory to be examined under a microscope to check for the presence of white blood cells and germs or to grow and identify the germs (urine culture).
  • Complete blood count may be done to check for a high white blood cell count, a possible sign of infection.
  • Blood may be tested to grow and identify any germs that may have spread from the urinary tract into the bloodstream (blood culture).
  • People who have recurrent UTIs may need additional tests eg. measurement of the amount of urine remaining in the bladder after urination is complete (residual urine).
  • Recurrent UTIs may also be evaluated by examining the anatomy of the urinary tract with imaging tests, such as an ultrasound.

Complications

  • Less often, germs may move up one of the ureters from the bladder, resulting in more serious infection of the kidney (pyelonephritis).
  • Occasionally, UTIs may spread into the bloodstream (sepsis), causing serious problems and even death.

Treatments

  • UTIs that produce symptoms are treated with antibiotics.
  • If fungi are causing the infection, antifungal drugs are used.
  • If a person has a UTI but does not have any symptoms, treatment is usually not necessary.
  • Antibiotics are usually taken by mouth.
  • For the treatment of pyelonephritis, antibiotics are sometimes given through a tube inserted into a vein (intravenously). People with diabetes, a weakened immune system, or an abnormality blocking the flow of urine may need prolonged antibiotic treatment.
  • Surgery or other procedures may be necessary to relieve physical blockages to the flow of urine or to correct structural abnormalities in the urinary tract. Draining urine from a blocked area can help control the infection and prevent kidney damage.

Recurrent UTIs

  • UTIs usually respond well to drug therapy.
  • However, a subsequent UTI may develop if the germs were not eliminated from the urinary tract during treatment.
  • A second infection caused by the same microorganism is called a relapse infection.
  • Infection by one type of germ may be followed quickly by an infection caused by a different germ.
  • One possible cause of a relapse or recurrent infection is failure to take antibiotics for proper duration or adequent dosage to eliminate the germ from the urinary tract.
  • Recurrent infections can occur when abnormalities persist in the urinary tract.

Prevention

  • Improvement of personal hygiene and increased fluid intake may help prevent UTIs.
  • Antibiotics are sometimes used to prevent recurrent infections.
  • In people who have had a urinary catheter inserted, the catheter is removed as soon as possible to prevent infection.
Last Review : 26 April 2012
Writer : Dr. Ho Bee Kiau
Reviewed : Dr. Ho Bee Kiau