Urinary tract infection

Alternative names
Bladder infection; Cystitis; UTI

Definition
A urinary tract infection, or UTI, is an infection that can happen anywhere along the urinary tract - the kidneys, the ureters (the tubes that take urine from each kidney to the bladder), the bladder, or the urethra (the tube that empties urine from the bladder to the outside).

Causes, incidence, and risk factors

Cystitis, a common condition, is usually caused by a bacteria from the anus 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.
In addition, the following risk factors increase the chances of getting a UTI:

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

Some children develop UTIs. In boys, they are most common before the first birthday. UTIs are more common among uncircumcised boys. 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.

Symptoms

The symptoms of a UTI include:

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

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

     
  • Painful sexual intercourse  
  • Penis pain  
  • Flank (side) pain, vomiting, or fever and chills (may be a sign of kidney involvement)  
  • 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)

Signs and tests
Tests generally include taking a urine sample:

     
  • A urinalysis commonly reveals white blood cells (WBC) or red blood cells (see also RBC - urine).  
  • A urine culture (clean catch) or catheterized urine specimen may be performed to determine the type of bacteria in the urine and the appropriate antibiotic for treatment.

TESTING IN CHILDREN

Because many children with cystitis have something abnormal about their anatomy that predispose them to infections, because these infections are usually preventable, and because the long-term consequences of repeated urinary tract infections in children can be quite serious, many children with cystitis need special imaging studies to determine why they got a urinary tract infection.

These studies usually include both 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 with 2 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 resolve 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 fatal complications.

Commonly used antibiotics include:

     
  • Nitrofurantoin  
  • Cephalosporins  
  • Sulfa drugs (sulfonamides)  
  • Amoxicillin  
  • Trimethoprim-sulfamethoxazole  
  • Doxycycline (should not be used under age 8)  
  • 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 hospitalization to receive hydration 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.

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

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 2 infections in 6 months or at least 3 in one 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

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

If you are prone to UTIs, your doctor may recommend taking antibiotics more regularly to prevent infection.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

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