Urinary tract infections are one of the most commonly occurring bacterial infections in medicine today and account for 7 million patient visits annually.(1) It is estimated that 20% of women will suffer with symptoms of a urinary tract infection some time in their lives, with many having more than one.(2) Infections of the urinary tract cover a wide variety of syndromes including urethritis, cystitis, prostatitis, and pyelonephritis.

Under normal circumstances, the urinary tract is pretty resistant to infection by bacteria. This is partly because of the very nature of urine itself. Urine has a very low pH, which along with its high concentration of urea and the manner in which it sets up or crosses membrane barriers, allows it to kill or at least slow the growth of many organisms. There are several ways in which professionals classify UTI's. One of these methods simply refers to where the infection is. Lower urinary tract infections include cystitis (bladder), urethritis (urethra), prostatitis (prostate gland), and epididymitis. Pyelonephritis is considered an upper urinary tract infection and involves the kidneys.

Another way to classify them is as either complicated or uncomplicated. Uncomplicated urinary tract infections involve a patient who lacks structural or functional abnormalities that interfere with normal urine flow. These infections occur most frequently in women of child bearing age who are otherwise healthy individuals. Complicated UTI's, on the other hand, are the result of something structural or functional such as a birth defect, an injury, a stone or obstruction, to name a few. When these and other conditions interfere with the normal flow of urine, then the condition is considered to be complicated. Complicated infections occur in both genders and frequently involve the upper and lower urinary tract.(3)

UTI's are disorders involving a repeated or prolonged bacterial infection of the bladder or lower urinary tract. Most urinary tract infections occur in the lower urinary tract, which includes the bladder and urethra. Cystitis occurs when bacteria, along with the accompanying inflammation infect the lower urinary tract which is normally a sterile environment. If an individual has frequent infections or if the infection does not respond to treatment, then the condition is considered chronic. Chronic or recurrent urinary tract infections include repeated episodes of cystitis, or urinary tract infections that do not respond to usual therapies or that last longer than two weeks. UTI's are most common in women; however, men and children may experience them as well.

About one in every five women will experience a UTI at least once in their lifetime, and many will have recurring infections. Also, the elderly population is at an increased risk for developing cystitis due to incomplete emptying of the bladder associated with many of the conditions that accompany aging. Also, a lack of adequate fluids, bowel incontinence, immobility or decreased mobility, and placement in a nursing home, all place the person at increased risk for developing cystitis.(4)

The majority of UTI's are caused by a single organism, however in complicated urinary tract infections, more than one organism may be the problem. There are several ways in which the bacteria can enter into the urinary tract with the ascending route being the most common. The source of those bacteria can be from fecal material, use of spermacides, and the use of diaphragms as contraception.(1) The fact that UTI's are more common in females than males due to the anatomic differences in location and length of urethra seems to support the theory that the ascending route is the most common acquisition route.

Descending (Hematogenous) spread is another route by which infection of the kidney may occur. This gener