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Development of Outbreak Investigation Database for hospital Infections Osaka University, Faculty of Medicine, JAPAN Kiyoko Makimoto, Ph.D., MPH What are hospital infections? • Two types of infections you find in the hospital – Hospital-acquired infections – Community-acquired infections • How can we distinguish them? – By latency period – CDC definition for NIs: development of infections after 48 hours of admission Brief history of hospital infections • First well documented hospital infections – In the middle of 1800 Lying-in Hospital in Vienna – Maternal mortality rates exceeded 10%, mainly due to puerperal fever (child-bed fever) endemic • Modern epidemiology of hospital infections – In 1950s, Staphylococcus aureus infection outbreaks in hospitals all over the world • Advances in 1970 • Intensive research in the 1990s What kinds of hospital infections exit? • Device-related – Blood stream infections (BSI) – Urinary tract infections (UTI) – Ventilator-associated pneumonia (VAP) • Procedure-related – Surgical site infections (SSI) • Environmental contamination – Water, disinfectant, etc. Devices and procedures as major sources of hospital infections Changes in flora due to antibiotic therapy :20-25% Others: 20% Respirators Cross-infections: 20-40% Surgeries Arterial/venous catheters Patients’ own flora: 40-60% Urinary catheters Why do we need to study hospital infections? • • • • Not all hospital infections are preventable, but they are associated with Excess length of hospital stay Excess cost Excess mortality Law suits Distribution of hospital infections by sites, SENIC study Urinary tract Surgical wound Pneumonia Bacteremia Other sites Increases in the mean length of hospital stay due to hospital infections in the U.S. , SENIC study Bacteremia Surgical wound Pneumonia Urinary tract Other sites All 0 1 2 3 4 Days 5 6 7 8 Excess cost of hospitalization due to hospital infections in the U.S., 1992 Pneumonia Bacteremia Surgical wound Urinary tract Other sites All 0 1000 2000 3000 U.S. dollars 4000 5000 6000 Who are at risk for acquiring hospital infections? • Patients in Intensive Care Units – ICU （medical, surgical, burn, Neonatal ICU、 Pediatric ICU) – Surgery department • Immunocompromised patients – Cancer treatment, transplant, HIV infections • Other factors – Age, smoking, chronic diseases Distribution of hospital infections by infection sites and endemic/outbreak status Urinary tract Surgical wound Pneumomia Hepatitis Gastroenteritis Cutaneous Bacteremia Other Endemic Outbreak Why do we need an outbreak investigation database? • Literature search is considered essential for outbreak investigation • Difficulty in collecting relevant articles in hospitals with limited resources • Shortage of health care workers trained in epidemiology in Japan • Epidemiology of hospital infections is not taught in school Conducting Medline search • Medline search yielded >600 articles between 1970 and 2000 • Only a small number of outbreak investigations reported all the information necessary to replicate the investigation • Recent investigations tend to focus on DNA typing to identify epidemic strains What kinds of outbreaks have been reported? • The largest number of people affected – Norwalk-like virus affected 635 employees (27% attack rate), 79 people affected in a single day – Am J Epidemiol. 1988 Jun;127(6):1261-71. • The longest duration – >= 10 years of unrecognized hospital transmission of legionnaires' disease among transplant patients (25 cases) – Infect-Control-Hosp-Epidemiol. 1998 Dec; 898-904 19(12): Continued • Unusual source of outbreak – Klebsiella pneumoniae producing ESBL transmitted by gel used for ultrasonography – 2 adults and 1 neonates were infected; 5 colonized – J-Clin-Microbiol. 1998 May; 36(5): 1357-60 • Outbreak due to non-infectious origin – Hemolysis (discolored, pink serum visualized in spun serum sample) due to defect products (30 cases in 11 days) – Kidney-Int. 2000 Apr; 57(4): 1668-74 What kinds of fields do we need? • • • • Mode of transmission Pathogens Type of investigation Place (NICU, ICU, surgery, etc.) • Country • Author • • • • Hospital size No. of patient affected No. of deaths Detail investigation process • Infection control and prevention strategies Usefulness of the Database I • A learning tool for epidemiologic and microbiologic investigations – Specific pathogens to look for in certain symptoms – Guide epidemiologic investigations • Identify study design in similar situations • Types of information to collect Epidemiologic skills required in complex investigations • Case definition – Able to learn how to write a case definition to find cases • Selection of controls in case-control studies – Selection of controls is the most difficult part Usefulness of the Database II • Provide infection prevention strategies by – pathogens – type of service – infectious diseases – mode of transmission, etc. Searching by Pathogens: Acinetobacter baumannii Any impacts of the database on Japanese culture? • Very few Japanese professionals report outbreak investigations • Reporting outbreaks to professional journals as professional and social obligation • Providing information in sufficient detail to help investigations Challenges • Currently 220 records have been entered • Changes in hospital practices affecting the outbreak investigation • Funding is necessary to complete and keep updating outbreak database Changes in hospital practices • Factors related to patients – Shorter hospital stay – Increased patients’ acuity – Increases in intra- and inter-hospital transfer • Factors related to health care workers – High turnover of nurses – Floating shift – Employment of temporary staff Your comments are greatly appreciate it URL for the outbreak investigation database http://health-db.net/infection/index.asp