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National Healthcare Disparities Report, 2005

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National Nosocomial Infections Surveillance (NNIS) System


U.S. Department of Health and Human Services, Centers for Disease Control and Prevention (CDC).

Mode of Administration

Participation in the NNIS System is voluntary and involves only acute care general hospitals in the United States. As of June, 2004 nearly 300 hospitals were participating in the NNIS System. Participation is limited to hospitals with 100 or more beds that meet minimum requirements for infection-control staffing.

The data are collected uniformly by trained infection-control personnel using surveillance protocols that target inpatients at high risk of infection and are reported routinely to CDC where they are aggregated into the database.

The standardized protocols, called "surveillance components," include adult and pediatric intensive care unit (ICU), high-risk nursery (HRN), and surgical patient. The components may be used singly or simultaneously, but once selected, they must be used for a minimum of one calendar month. All infections are categorized into major and specific infection sites using standard CDC definitions that include laboratory and clinical criteria.

Primary Content

Adult and pediatric intensive care units (ICUs): all sites of nosocomial infection in patients located in ICUs.

High-risk nurseries (HRNs): all sites of nosocomial infection in patients located in HRNs.

Surgical patients: all infections or surgical-site infections (SSI) of patients undergoing operative procedures on the NNIS list.

Demographic Data

Age, gender.

Years Collected

Since 1970.


Data reported monthly; aggregate report published annually.

Contact Information

Agency homepage:

Data system homepage:


National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2004, issued October 2004. Am J Infect Control 2004; 32:470-85. Also available at



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