Overview of the causes and types of recurrent cystitis

Abstract

Bacterial cystitis accounts for the majority of urinary tract infection (UTI). It is frequently found in young, otherwise healthy females showing no signs of anatomical or physiological urinary tract defects. Among young women who have experienced an episode of acute bacterial cystitis, 25% to 50% develop recurrent episodes. Individuals with recurrent cystitis episodes have a greater susceptibility to urogenital colonization with uropathogens that thrive by adhering to uroepithelial cells. Further, there is an increased likelihood of infection with an antibiotic resistant uropathogen due to previous antimicrobial therapy for recurring infections. At each step of the pathogenesis, different host genetic, biologic, and behavioral factors, and bacterial factors interact and influence susceptibility to recurrent cystitis. Behavioral factors like sexual intercourse, use of spermicidal contraceptives and history of recurrent cystitis are major independent risk factors for recurrent cystitis infections. In post-menopausal women without comorbidities, estrogen depletion is mainly responsible for increased susceptibility to recurrent cystitis. Certain strain-specific bacterial virulence determinants may also contribute to recurrent cystitis by providing a selective advantage. Phenotypically, recurrent cystitis is categorized as reinfection or bacterial persistence. Majority of recurrent cystitis cases seen in men occur due to structural or functional abnormalities of the urinary bladder which allows same pathogens from the same site in the bladder to cause recurrences due to bacterial persistence. The concept of ‘uncomplicated’ and ‘complicated’ recurrent cystitis is used for classification of recurrent cystitis cases, similar to UTIs. Uncomplicated recurrent cystitis comprises cases occurring in young, healthy, nonpregnant women, mainly due to uropathogenic Escherichia coli. Due to the unique spectrum of host-bacterial interactions in the urinary tract, the distinction between complicated and uncomplicated recurrent cystitis is not straightforward. ‘Complicating’ factors such as structural, obstructive, neoplastic, functional, and neurological abnormalities of the urinary tract, systemic conditions including pregnancy, and certain demographic factors are attributed in the development of complicated recurrent bacterial cystitis.