Complicated urinary tract infections.

Urinary infections complicated by structural anomalies, metabolic alterations, abnormalities of host response, or unusual or difficult-to-treat pathogens commonly occur in our practices. Therapeutic regimens for most of these patient populations are empiric and unproven. Our understanding of specific microbial virulence factors is inadequate. Until well-designed interventions are proven, management strategies will depend on clinical biases and "trial and error" therapeutic attempts. Presumably, over the course of the next decade, better answers will emerge that will improve our ability to prevent and more adequately manage our patients with complicated UTIs.