Understanding Urinary Tract Infections - Diagnosis and Treatment

How Do I Know If I Have a Urinary Tract Infection?

Most urinary tract infections can be diagnosed by taking a good history of the patient's symptoms and examining a urine specimen for white blood cells, blood and bacteria (urinalysis). A clean-catch urine specimen is needed, meaning that the patient must carefully clean the opening to the urethra, begin urinating into the toilet and then catch urine in a sterile cup.

Chemically treated test sticks can be dipped into the urine to identify abnormalities in the urine (such as pus, blood, and/or bacteria). If the urine dip is positive, then the healthcare provider may begin the patient on an antibiotic while awaiting the final results of the urine culture. A urine culture is an additional test which can determine the number and specific type of bacteria causing the infection, as well as help determine which antibiotic can best treat it. In girls or young women, a culture is frequently unnecessary.

Other tests may be ordered if the practitioner suspects that there is some other problem causing the urinary tract infection (such as a kidney stone or a condition called reflux, in which the urine backs up abnormally from the bladder toward the kidneys), or if there is a history of recurrent infections.

Because urinary tract infections in men are quite rare, most men who are diagnosed with a urinary tract infection will be advised to have other tests to determine if some other abnormality is responsible.

Other tests may include:

• Blood tests
• Ultrasound examination of the urinary tract
• X-rays of the kidneys, ureters, and bladder (called a KUB)
• CT scans
• Cystoscopy, in which a thin, flexible fiber-optic tube is inserted up the urethra to examine the inside of the bladder
• Intravenous pyelogram (an X-ray test using dye to better outline the urinary system)
• Voiding cystourethrography (in which radioactive material or dye is used to highlight the urinary system, and X-rays are taken as the bladder is filled, and as the patient urinates)

What Are the Treatments?

Most cases of simple acute cystitis in young women can be treated with a three-day course of an antibiotic. Recurrence of symptoms is cause often for more sophisticated dignostic studies to rule out more significant problems.

Certain risk factors warrant a longer course of antibiotic treatment. Pregnant women, patients with diabetes, patients known to have kidney stones or other obstructions to the free flow of urine, and individuals who have had symptoms for longer than a week should all be given a seven- or 10-day course of antibiotics. In men with prostatitis, or anyone with a kidney infection (pyelonephritis), the antibiotics should be given for at least several weeks.

The type of antibiotic used depends on the type of bacteria found in the urine culture. Effective antibiotics include trimethoprim-sulfamethoxazole, ciprofloxacin, levofloxacin or nitrofurantoin.