Host defense mechanism in the pathogenesis of UTI and UTI in immunocompromised patients.

Defects in the immune system determine the clinical manifestations and severity of urinary tract infections (UTI) and the rates of complication but they only have an indirect role in influencing susceptibility to infection. The rates of UTI in diabetics, renal transplant, recipients, neutropenic patients, and patients with AIDS are primarily determined by the degree and duration of urinary tract manipulation and the higher perineal prevalence of potential pathogens that result from frequent hospitalization and antimicrobial use. Prompt recognition and treatment of established infections is critical to prevent life-threatening complications (e.g. bacteremia, emphysematous pyelonephritis) but routine screening for asymptomatic bacteriuria is indicated only in kidney recipients less that 3 months post-transplantation.