Methodologies used in surveillance of surgical wound infections and bacteremia in Australian hospitals

Background: The prevalence of nosocomial infection in Australian hospitals is estimated to be between 5.5% and 6.38. Since 1989, infection control pro fessionals (ICPs) in hospitals accredited by the Australian Council on Heal th Care Standards (ACHS) have been encouraged to collect nosocomial infecti on data according to ACHS methodology. Method: In 1996, we surveyed members of the Australian Infection Control As sociation to examine the time spent on surveillanee, the practice of survei llance of all hospital infections (hospital-wide surveillance), case-findin g methods, case definitions, and reporting routinely used by ICPs in acute care hospitals. We also examined the ICPs' education and experience in infe ction control (IC). Results: The survey was completed and returned by 65% (644 of 993) of Austr alian Infection Control Association members. Of the ICPs who completed the survey, 47.8% (308 of 644; 95% CI, 43.9%-51.7%) met the criteria for inclus ion, because they coordinated an IC program in an acute care or surgical ho spital and performed surveillance for either surgical wound infection, intr avascular device-related bacteremia, or non-device-related bacteremia. Of t he ICPs who reported their facility's accreditation status, 93.5% participa ted in ACHS system. Most (97.6%) ICPs had completed hospital-based general registered nurse training. Only 1.9% (6 of 308) of ICPs reported completion of continuing education relating to hospital epidemiology. The number of y ears of IC experience ranged from zero to 35 years, with a median of 4 year s. ICPs spent a substantial proportion of their total weekly IC time on sur veillance irrespective of ACHS accreditation; 19.5 hours in ACHS hospitals and 15.6 hours in non-ACHS hospitals (P = .33). More than three quarters (7 6.0%) of ICPs performed hospital-wide surveillance. The case-finding method s, definitions of infections, and reporting formats varied greatly. The def inition most commonly applied by ICPs (6.8%; 95% CI, 4.1%-10.4%) to define surgical wound infection was infection within 30 days after the operative p rocedure, plus purulent drainage, plus isolation of organisms from a cultur e from the incision site, plus diagnosis by a medical officer. A 5-item def inition of a patient being asymptomatic, plus afebrile on admission, plus i nfection occurring at least 48 hours after admission, plus the patient havi ng a fever of >38 degrees C, plus a recognized culture from one or more bot tles was used by 15.7% (95% CI, 11.3%-21.0%) of ICPs to define a case of ba cteremia. Conclusion: Surveillance is the core business of Australian ICPs and consum es a substantial proportion of their time. The importance of surveillance, the epidemiologic limitations of the current ACHS system, and the nonstanda rd methods we report indicate that improved methodology is required for cas e finding and reporting of nosocomial infections. Australian ICPs should co mplete training in the principles of surveillance and epidemiology. With th is training, ICPs can work collaboratively with Ether health care professio nals to develop epidemiologically sound, local, nosocomial surveillance sys tems and lobby for a voluntary, national, standardized, risk-adjusted syste m of targeted nosocomial surveillance.