Infectious complications: general background

Urinary tract infection represents almost 40% of all healthcare-associated infections, with the vast majority due to the indwelling urinary catheter.  Over 900,000 patients develop a catheter-associated urinary tract infection (CAUTI) in a U.S. hospital each year.  Urinary catheter-related infection leads to substantial morbidity. The incidence of bacteriuria in catheterized patients is about 5% per day.  Among patients with bacteriuria, 10 to 20% will develop symptoms of local infection, while 1 to 4% will develop bloodstream infection. The urinary tract is implicated as the source in 11 to 40% of hospital-acquired bacteremic episodes. 

The presentation of catheter-associated infection varies from asymptomatic bacteriuria to overwhelming sepsis and even death.  Clinical manifestations of CAUTI may include such local symptoms as lower abdominal discomfort or flank pain, or systemic symptoms such as nausea, vomiting, and fever. Patients with bloodstream infection may present with fever, confusion, and hypotension.

A key first step leading to CAUTI is the colonization of the catheter with organisms.  Indeed, urinary catheters readily develop biofilm – a collection of microbial organisms on a surface that is surrounded by an extracellular matrix – on their inner and outer surfaces once they are inserted. Such biofilm provides a protective environment for microorganisms.

Many of the infectious complications of the urinary catheter could be prevented by using the catheter only when necessary and promptly removing it when no longer needed.