Redefining Catheter-Associated Nosocomial Urinary Tract Infections: Are New Definitions Necessary?

Abstract

ISSUE: Centers for Disease Control and Prevention (CDC) definitions of urinary tract infection (UTI) have not been updated since 1988 and are not designed specifically for surveillance of nosocomial catheter-association UTIs (CA-NUTIs). Given the emphasis on device-related infections, a specific algorithm was developed to address CA-NUTI surveillance. PROJECT: Surveillance data from 20 hospitals (over 5,000 records) was reviewed. Surveillance included laboratory data, physician progress notes and orders, pharmacy records, and nursing notes (including emergency and operating room records). Analysis of documented symptoms, clinical indicators, and treatment patterns was conducted to determine which criteria were most frequently found. After review of the data a group of nine infection control specialists, all with extensive experience in conducting CA-NUTI surveillance, met to discuss current CDC definitions and to develop new/revised definitions. Efforts were made to incorporate existing UTI definitions (CDC and Long-Term Care) when possible. RESULTS: Due to the presence of a Foley catheter, symptoms typically associated with UTI are rarely manifested (frequency, urgency, dysuria). While fever is often noted, it is not always present in CA-NUTI patients. Many indicators not presently used in the CDC definitions are triggers for CA-NUTI work-up. These indicators include cloudy or foul-smelling urine, leukocytosis, elevated temperature (not over 100.4), and change in mental status. Physicians are more likely to treat patients with low-colony counts who exhibit some indicator of infection and are less likely to treat those with high colony counts that have no indicators present. Discrepancies between current CDC definitions and lab practices make it difficult to apply certain definitions. LESSONS LEARNED: Current surveillance definitions do not address device-related UTIs. Development of an algorithm used specifically for CA-NUTIs has allowed us to more accurately assess infection rates based on symptoms, clinical indicators, laboratory data, and treatment patterns.