Cystitis; acute bacterial

Alternative names:

infection of bladder - acute; infection of urinary tract - acute; uncomplicated urinary tract infection; urinary tract infection - acute; UTI - acute

Definition:

A disorder involving bacterial infection of the bladder or lower urinary tract.

Causes, incidence, and risk factors:

Cystitis is caused when the normally sterile lower urinary tract (urethra and bladder) is infected by bacteria, with resultant inflammation. It is very common, occurring in 2 out of 100 people. The disorder is most common in sexually active women ages 20 to 50, but may occur in those not sexually active or in young girls. Cystitis is rare in males with anatomically normal urinary tracts. Females are more prone to the development of cystitis because of their relatively shorter urethra--bacteria do not have to travel as far to enter the bladder--and because of the relatively short distance between the urethral opening and the anus. Older adults are at high risk for developing cystitis, with the incidence in the elderly being as high as 33 out of 100 people.

Over 90% of cases of cystitis are caused by E. coli, a bacterium found in the lower gastrointestinal tract. Sexual intercourse can increase the risk of cystitis because bacteria can be introduced into the bladder through the urethra during sexual activity. Once bacteria enter the bladder, they normally are removed through urination. When bacteria multiply faster than they are removed by urination, infection results.

Risks for cystitis include obstruction of the bladder or urethra with resultant stasis of urine, insertion of instruments into the urinary tract (such as catheterization or cystoscopy), pregnancy, diabetes, and a history of analgesic nephropathy or reflux nephropathy.

The elderly population are at increased risk for developing cystitis due to incomplete emptying of the bladder associated with such conditions as benign prostatic hyperplasia (BPH), prostatitis, and urethral strictures. Also, 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.