Uncomplicated and complicated urinary tract infections in adults: the infectious diseases's specialist perspective

Urinary tract infection (UTI) is one of the most common bacterial infections either in the outpatient and inpatient (hospitalized) setting. Women are more commonly affected than men. The distinction between uncomplicated and complicated UTI is based on gender and/or presence of risk factors, and it is used to guide the choice and duration of antibiotic treatment. Acute cystitis and pyelonephritis in healthy premenopausal non-pregnant women without urinary tract abnormality are classified as uncomplicated. All others are considered complicated UTI. Clinical classification is based on a continuum with cystitis as the less severe form and urosepsis the most severe. Escherichia coli remains the microorganism more frequently responsible for UTI but with different prevalence according to characteristic of host and the epidemiology (community-acquired or healthcare associated). Empirical treatment of uncomplicated and complicated UTI is becoming increasingly challenging due to the widespread emergence of resistance to several class of antibiotics (fluoroquinolones, trimethoprim-sulfamethoxazole, beta-lactams). Of even great concern is the emergence of carbapenemase-producing Enterobacteriaceae that leaves few or no alternatives for treatment of nosocomial UTI.