Definitions of Health Care-Associated Infections

The Centers for Disease Control and Prevention (CDC) developed baseline definitions for HAIs that were republished in 2004.19 HAIs were defined as those that develop during hospitalization but are neither present nor incubating upon the patient’s admission to the hospital; generally for those infections that occur more than 48 to 72 hours after admission and within 10 days after hospital discharge. Some hospitals use these definitions exactly as written; other hospitals may use some but not all of the CDC definitions; and other health care facilities may need to modify or develop their own definitions. Whatever definition is used, it should be consistent within the institution and be the same or similar to those developed by CDC or those used by other investigators. Having standard definitions is useful if the health care facility wants to compare surveillance results or performance measures within its various medical/surgical specialties, against those of other health care institutions, or with national published data.