Urinary Tract Infection

Many factors predispose older adults to bacteriuria and symptomatic UTI. In older women, loss of estrogen’s protective effect on the genitourinary mucosa results in increased colonization of the vagina with uropathogens (Baldassare and Kaye; Nicolle, 1992). Relaxation of pelvic muscles and the presence of such genitourinary abnormalities as prolapse of the bladder or rectum into the vagina and bladder diverticula outpouching lead to inefficient bladder emptying and allow multiplication of bacteria in the residual urine (Sobel and Kaye; Baldassare and Kaye; Nicolle, 1992). Prostatic hypertrophy in older men leads to outlet obstruction, resulting in increased residual urine volume. Increased prostate size also leads to turbulent flow within the urethra, which facilitates entry of bacteria into the urethra and bladder. The presence of chronic bacterial prostatitis often makes sustained eradication of pathogens from the urine difficult and contributes to the high relapse rate of bacteriuria in treated men (Baldassare and Kay; Marrie et al.). The increased burden of comorbid illness in institutionalized older adults is commonly associated with functional impairment. Immobility and urinary and fecal incontinence contribute to the higher prevalence of bacteriuria and UTI observed in this population (Nicolle, 1993). In addition, the use of indwelling urinary catheters is a significant risk factor for bacteriuria in this population. Even with meticulous catheter care and a closed drainage system, all patients with chronic indwelling catheters eventually become bacteriuric (Nicolle, 1993). Condom catheters are a potential predisposing factor for UTIs in older men and may also lead to soft-tissue infection of the penis (Warren).