Complicated urinary tract infections (CUTIs) are those infections diagnosed in individuals with structural or functional abnormalities of the genitourinary tract. Factors that may contribute to complicated infections include indwelling catheters, neurogenic bladder, renal failure, obstructive uropathy, urinary retention, and pregnancy. It is estimated that complicated UTIs comprise less than five percent of cases of UTIs.
Escherichia coli is the causative agent in almost all cases of uncomplicated UTI and about 60 percent of cases of complicated UTI. A wide variety of other gram-negative and gram-positive bacteriacan also cause CUTI, including, Klebsiella pneumonia, Proteus mirabilis, Providencia species, Pseudomonas aeruginosa, Enterococcus species, and Coagulase-negative staphylococcus. Overall, UTI is one of the most common bacterial infections in both the community and healthcare settings. Catheter-associated UTI is the most frequently occurring nosocomial infection As a result of its high incidence, the economic burden associated with urinary tract infection is substantial. Symptomatic catheter-associated UTI has been associated with an increased hospital stay of 1-2 days at an additional minimal cost of $676 per patient