T. Grace Emori

CDC definitions for nosocomial infections, 1988

The Centers for Disease Control (CDC) has developed a new set of definitions for surveillance of nosocomial infections. The new definitions combine specific clinical findings with results of laboratory and other tests that include recent advances in diagnostic technology; they are formulated as algorithms. For certain infections in which the clinical or laboratory manifestations are different in neonates and infants than in older persons, specific criteria are included. The definitions include criteria for common nosocomial infections as well as infections that occur infrequently but have serious consequences. The definitions were introduced into hospitals participating in the CDC National Nosocomial Infections Surveillance System (NNIS) in 1987 and were modified based on comments from infection control personnel in NNIS hospitals and others involved in surveillance, prevention, and control of nosocomial infections. The definitions were implemented for surveillance of nosocomial infections in NNIS hospitals in January 1988 and are the current CDC definitions for nosocomial infections. Other hospitals may wish to adopt or modify them for use in their nosocomial infections surveillance programs.

CDC Definitions of Nosocomial Surgical Site Infections, 1992: A Modification of CDC Definitions of Surgical Wound Infections

In 1988, the Centers for Disease Control (CDC) published definitions of nosocomial infections However, because of journalistic style and space constraints, these definitions lacked some of the detail provided to National Nosocomial Infections Surveillance (NNIS) System hospitals in the NNIS Manual (unpublished). After the NNIS System hospitals had had considerable experience with the definitions and in response to a request for review by The Surgical Wound Infection Task Force, a group composed of members of The Society for Hospital Epidemiology of America, the Association for Practitioners in Infection Control, the Surgical Infection Society, and the CDC, we slightly modified the definition of surgical wound infection and changed the name to surgical site infection (SSI).

National nosocomial infections surveillance system (NNIS): Description of surveillance methods

The National Nosocomial Infections Surveillance System (NNIS) is an ongoing collaborative surveillance system sponsored by the Centers for Disease Control (CDC) to obtain national data on nosocomial infections. The CDC uses the data that are reported voluntarily by participating hospitals to estimate the magnitude of the nosocomial infection problem in the United States and to monitor trends in infections and risk factors. Hospitals collect data by prospectively monitoring specific groups of patients for infections with the use of protocols called surveillance components. The surveillance components used by the NNIS are hospitalwide, intensive care unit, high-risk nursery, and surgical patient. Detailed information including demographic characteristics, infections and related risk factors, pathogens and their antimicrobial susceptibilities, and outcome, is collected on each infected patient. Data on risk factors in the population of patients being monitored are also collected; these permit the calculation of risk-specific rates. An infection risk index, which includes the traditional wound class, is being evaluated as a predictor of the likelihood that an infection will develop after an operation. A major goal of the NNIS is to use surveillance data to develop and evaluate strategies to prevent and control nosocomial infections. The data collected with the use of the surveillance components permit the calculation of risk-specific infection rates, which can be used by individual hospitals as well as national health-care planners to set priorities for their infection control programs and to evaluate the effectiveness of their efforts. The NNIS will continue to evolve in finding more effective and efficient ways to assess the influence of patient risk and changes in the financing of health care on the infection rate.

Definitions of key terms used in the NNIS System.

For valid comparisons with the published NNIS nosocomial infection rates, hospitals must define data elements in the same way. Definitions for infections, risk factors, and populations monitored are specified in the NNIS System, but thus far only infection definitions and the list of NNIS operative procedure categories have been published. This article defines other key terms used in the NNIS System.

Update from the SENIC project: Hospital infection control: Recent progress and opportunities under prospective payment

From a survey of all U.S. hospitals in 1976 and of a random sample in 1983, we found that the intensity of infection surveillance and control activities greatly increased, and the percentage of hospitals with an infection control nurse per 250 beds increased from 22% to 57%. The percentage with a physician trained in infection control remained low (15%), and there was a drop in the percentages of hospitals doing surgical wound infection surveillance (from 90% down to 79%) and reporting surgeon-specific rates to surgeons (from 19% down to 13%). There was an increase in the percentage of hospitals with programs shown to be effective in preventing urinary tract infections, bacteremias, and pneumonias, but not surgical wound infections. The percentage of nosocomial infections being prevented nationwide appears to have increased from 6% to only 9%, whereas 32% could be prevented if all hospitals adopted the most effective programs.

The national nosocomial infections surveillance system: Plans for the 1990s and beyond

The National Nosocomial Infections Surveillance (NNIS) System is an ongoing collaborative surveillance system among the Centers for Disease Control (CDC) and United States hospitals to obtain national data on nosocomial infections. This system provides comparative data for hospitals and can be used to identify changes in infection sites, risk factors, and pathogens, and develop efficient surveillance methods. Data are collected prospectively using four surveillance components: hospital-wide, intensive care unit, high-risk nursery, and surgical patient. The limitations of NNIS data include the variability in case-finding methods, infrequency or unavailability of culturing, and lack of consistent methods for post-discharge surveillance. Future plans include more routine feedback of data, studies on the validity of NNIS data, new components, a NNIS consultant group, and more rapid data exchange with NNIS hospitals. Increasing the number of NNIS hospitals and cooperating with other agencies to exchange data may allow NNIS data to be used better for generating benchmark nosocomial infection rates. The NNIS system will continue to evolve as it seeks to find more effective and efficient ways to measure the nosocomial infection experience and assess the influence of patient risk, changes in the delivery of hospital care, and changes in infection control practices on these measures.

Does Using a Laparoscopic Approach to Cholecystectomy Decrease the Risk of Surgical Site Infection

ObjectiveTo assess the impact of laparoscopy on surgical site infections (SSIs) following cholecystectomy in a large population of patients Summary Background DataPrevious investigations have demonstrated that laparoscopic cholecystectomy is associated with a shorter postoperative stay and fewer overall complications. Less is known about the impact of laparoscopy on the risk for SSIs. MethodsEpidemiologic analysis was performed on data collected during a 7-year period (1992–1999) by participating hospitals in the National Nosocomial Infections Surveillance (NNIS) System in the United States. ResultsFor 54,504 inpatient cholecystectomy procedures reported, use of the laparoscopic technique increased from 59% in 1992 to 79% in 1999. The overall rate of SSI was significantly lower for laparoscopic cholecystectomy than for open cholecystectomy. Overall, infecting organisms were similar for both approaches. Even after controlling for other significant factors, the risk for SSI was lower in patients undergoing the laparoscopic technique than the open technique. ConclusionsLaparoscopic cholecystectomy is associated with a lower risk for SSI than open cholecystectomy, even after adjusting for other risk factors. For interhospital comparisons, SSI rates following cholecystectomy should be stratified by the type of technique.

Comparison of surveillance and control activities of infection control nurses and infection control laboratories in United States hospitals, 1976–1977

To study the impact of the professional background of infection control personnel, we compared the characteristics and activities of 107 infection control nurses (ICNs) with those of 13 infection control laboratorians (ICLs), all in hospitals with 300 beds or more. Although the two groups performed similarly in many respects. ICNs spent more time teaching, whereas ICLs spent more time and appeared more proficient in investigating outbreaks. Staff nurses at hospitals with ICNs found the infection control person more visible on the wards and more available for discussing infection control matters. ICNs appeared less hesitant to speak up to personnel not following correct handwashing techniques. ICNs and ICLs appear to offer different skills that should be considered when filling different infection control positions.