 Introduction/Background A urinary tract infection (UTI) is an infection of the urinary system causing an inflammatory response. A UTI occurs when the normal flora of the periurethral area are replaced by uropathogenic bacteria, which ascend, causing bacterial cystitis. Less commonly, this infection ascends to the kidney to cause bacterial pyelonephritis [1]. The overall lifetime risk of UTI for women is >50% [2]. An uncomplicated UTI is classified as a UTI without structural or functional abnormalities of the urinary tract and without relevant comorbidities. It should be noted that although uncomplicated UTI includes both lower tract infection (cystitis) and upper tract infection (pyelonephritis), repeated pyelonephritis should prompt consideration of a complicated etiology [1]. Complicated UTIs are those occurring in patients with underlying structural or medical problems [3,4]. Anatomical abnormalities include cystoceles, bladder or urethral diverticula, fistulae, indwelling catheters, urinary tract obstruction and underlying conditions such as voiding dysfunction, pregnancy, diabetes, and immunosuppression. Other documented risk factors include prior urinary tract surgery or trauma, gross hematuria after infection resolution, urea-splitting bacteria on culture, prior abdominopelvic malignancy, prior urinary tract calculi, prior diverticulitis, symptoms of pneumaturia, fecaluria, or repeated pyelonephritis. In the nonobstructed, nonpregnant woman, uncomplicated UTI is usually treated empirically and responds to appropriate antimicrobial therapy [2,5]. A UTI is considered recurrent when it follows the complete clinical resolution of a previous UTI [6]. Recurrent lower UTIs are usually defined as at least three episodes of infection within the preceding 12 months [3]. Recurrent UTIs involve reinfection from a source outside of the urinary tract or from bacterial persistence [1-3].
Recurrent Lower Urinary Tract Infections in Females.  Introduction/Background A urinary tract infection (UTI) is an infection of the urinary system causing an inflammatory response. A UTI occurs when the normal flora of the periurethral area are replaced by uropathogenic bacteria, which ascend, causing bacterial cystitis. Less commonly, this infection ascends to the kidney to cause bacterial pyelonephritis [1]. The overall lifetime risk of UTI for women is >50% [2]. An uncomplicated UTI is classified as a UTI without structural or functional abnormalities of the urinary tract and without relevant comorbidities. It should be noted that although uncomplicated UTI includes both lower tract infection (cystitis) and upper tract infection (pyelonephritis), repeated pyelonephritis should prompt consideration of a complicated etiology [1]. Complicated UTIs are those occurring in patients with underlying structural or medical problems [3,4]. Anatomical abnormalities include cystoceles, bladder or urethral diverticula, fistulae, indwelling catheters, urinary tract obstruction and underlying conditions such as voiding dysfunction, pregnancy, diabetes, and immunosuppression. Other documented risk factors include prior urinary tract surgery or trauma, gross hematuria after infection resolution, urea-splitting bacteria on culture, prior abdominopelvic malignancy, prior urinary tract calculi, prior diverticulitis, symptoms of pneumaturia, fecaluria, or repeated pyelonephritis. In the nonobstructed, nonpregnant woman, uncomplicated UTI is usually treated empirically and responds to appropriate antimicrobial therapy [2,5]. A UTI is considered recurrent when it follows the complete clinical resolution of a previous UTI [6]. Recurrent lower UTIs are usually defined as at least three episodes of infection within the preceding 12 months [3]. Recurrent UTIs involve reinfection from a source outside of the urinary tract or from bacterial persistence [1-3].