Health Encyclopedia

Urinary tract infection

Definition

A urinary tract infection, or UTI, is an infection that can happen anywhere along the urinary tract. The urinary tract includes the:

Bladder
Kidneys
Ureters -- the tubes that take urine from each kidney to the bladder
Urethra -- the tube that empties urine from the bladder to the outside

Alternative Names

Bladder infection; Cystitis; UTI

Causes, incidence, and risk factors

Cystitis, a common condition, is usually caused by bacteria entering the urethra and then the bladder. This leads to inflammation and infection in the lower urinary tract.

Certain people are more likely to get UTIs. Women tend to get them more often because their urethra is shorter and closer to the anus. Elderly people (especially those in nursing homes) and people with diabetes also get more UTIs.

Some children develop UTIs. In boys, they are most common before the first birthday. In young girls, UTIs are most common around age 3, overlapping with the toilet training period.

Cystitis in children can be promoted by abnormalities in the urinary tract. Therefore, children with cystitis, especially those under age 5, deserve special follow-up to prevent later kidney damage.

The following risk factors increase your chances of getting a UTI:

Bowel incontinence
Catheterization
Kidney stones
Immobility (for example, during recovery from a hip fracture)
Menopause
Narrowed urethra
Not drinking enough fluids
Pregnancy
Prostate inflammation or enlargement
Sexual intercourse, especially if you have multiple partners
Using a diaphragm for birth control

Symptoms

The symptoms of a UTI include:

Cloudy urine
Blood in the urine
Foul or strong urine odor
Frequent or urgent need to urinate
Need to urinate at night
Pain or burning with urination
Pressure in the lower pelvis

Young children with UTIs may only have a fever, or no symptoms at all.

Additional symptoms may include:

Mental changes or confusion (in the elderly, mental changes or confusion often are the only signs of a urinary tract infection; possible spread to the blood should be considered)
Flank (side) pain, vomiting, fever, and chills (may be a sign of kidney involvement)
Painful sexual intercourse
Penis pain

Signs and tests

Tests generally include taking a urine sample.

Urinalysis commonly reveals nitrates, white blood cells, and red blood cells. See also: RBC - urine

A urine culture (clean catch) or catheterized urine specimen may be done to determine the type of bacteria in the urine and the appropriate antibiotic for treatment.

TESTING IN CHILDREN

Many children with cystitis need special imaging studies to determine why they got a urinary tract infection. Many of them have something abnormal about their anatomy that predispose them to infections. The long-term consequences of repeated urinary tract infections in children can be quite serious. However, these infections can usually be prevented.

Special studies usually include an ultrasound of the kidneys and an x-ray taken during urination (called a voiding cystourethrogram or VCUG).

Most experts recommend this evaluation for:

Girls over age 5 who have had two or more urinary tract infections
All boys with their first urinary tract infection
All children who have a fever along with their urinary tract infection
All children under age 5 with their first urinary tract infection

Treatment

A mild case of cystitis may go away on its own without treatment. Because of the risk of the infection spreading to the kidneys, however, antibiotics are usually recommended. It is important that you finish the entire course of prescribed antibiotics.

In children, cystitis should be treated promptly with antibiotics to protect their developing kidneys. In the elderly, prompt treatment is recommended due to the greater chances of deadly complications.

Commonly used antibiotics include:

Amoxicillin
Doxycycline (should not be used under age 8)
Cephalosporins
Nitrofurantoin
Sulfa drugs (sulfonamides)
Trimethoprim-sulfamethoxazole
Quinolones (should not be used in children)

Most non-elderly adult women only need 3 days of antibiotics. If the infection has spread to one of the kidneys, you may need to be admitted to a hospital so you can receive fluids and antibiotics through a vein.

A chronic or recurrent UTI should be treated thoroughly because of the chance of kidney infection. Antibiotics may need to be given for a long period of time (as long as 6 months to 2 years), or stronger antibiotics may be needed than for single, uncomplicated episodes of cystitis.

Phenazopyridine hydrochloride (Pyridium) may be used to reduce the burning and urgency associated with cystitis. In addition, acidifying medications such a ascorbic acid may be recommended to decrease the concentration of bacteria in the urine.

If an anatomical abnormality is present, surgery to correct the problem may be recommended.

Expectations (prognosis)

Cystitis is uncomfortable, but usually responds well to treatment.

Complications

Chronic or recurrent urinary tract infection -- defined as at least two infections in 6 months or at least three in 1 year
Complicated UTI
Kidney infection

Calling your health care provider

Call your doctor if you, or your child, have symptoms of a UTI. Call right away if there is fever or chills, back or side pain, or vomiting. These symptoms suggest a possible kidney infection.

Also call if:

You have diabetes or are pregnant
There is discharge from the penis or vagina
The penis or vagina is painful, or sexual intercourse is painful
You suspect a child may have been sexually abused
There is blood or pus in the urine
The symptoms come back a short time after treatment with antibiotics

Prevention

Do NOT douche or use similar feminine hygiene products.
Do NOT drink fluids that irritate the bladder, like alcohol and caffeine.
Drink cranberry juice or use cranberry tablets, but NOT if you have a personal or family history of kidney stones.
Drink plenty of fluids.
Keep your genital area clean.
Urinate after sexual intercourse.
Wear cloth undergarments.
Wipe from front to back.

Use of low-dose antibiotics on a daily basis may be recommended to prevent UTIs if you get frequent infections.

References

Cincinnati Children's Hospital Medical Center. Evidence-based care guideline for medical management of first urinary tract infection in children 12 years of age or less. Cincinnati (OH): Cincinnati Children's Hospital Medical Center; 2006 Nov. 23 p.

Walsh, PC, ed. Campbell’s Urology. 8th ed. Philadelphia, Pa: Saunders; 2002.

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th ed. St. Louis, Mo: Mosby; 2002.

Review Date:7/23/2007
Reviewed By:Marc Greenstein, DO, Urologist, North Jersey Center for Urologic Care, Denville, NJ. Review provided by VeriMed Healthcare Network.

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