F. Kasuga 1 st Int Conf MRA Archiving of food samples from restaurants and caterers Fumiko Kasuga National Institute of Health Sciences, Japan (National Institute of Infectious Diseases)

F. Kasuga 1 st Int Conf MRA  An example of data collection for Hazard Characterization  Analysis of outbreak data in Japan

F. Kasuga 1 st Int Conf MRA Hazard Characterization describes, Pathogen concerned –serotypes, virulence, toxins, etc Population involved, susceptible, at risk Vehicle foods –contaminated, protect pathogens against stomach acid, inactivate pathogens or inhibit proliferation Dose response: how likely to get ill?

F. Kasuga 1 st Int Conf MRA Data for dose-response Pathogen dose ingested –concentration in food –food amount taken Attack rate (or P(infection), P(death), etc.) –population exposed –infected, ill, dead, etc.

F. Kasuga 1 st Int Conf MRA Data source for dose-response * Outbreak data has limitations, needs assumptions when used, but reflects real-world events.

F. Kasuga 1 st Int Conf MRA What we have experienced…

F. Kasuga 1 st Int Conf MRA MRA 00/03 Joint FAO/WHO Expert Consultation on Risk Assessment of Microbiological Hazards in Foods FAO Headquarters, Rome, Italy July Preliminary Report - Hazard Identification and Hazard Characterization of Salmonella in broilers and eggs Food and Agriculture Organization of the United Nations World Health Organization

F. Kasuga 1 st Int Conf MRA Beta-Poisson model for Salmonella spp. derived using outbreak data

F. Kasuga 1 st Int Conf MRA Why was it possible?

F. Kasuga 1 st Int Conf MRA Japanese Directive "Control measures against foodborne outbreaks"  issued  in march 1997  by Director General of Environmental Sanitation Bureau of the Japanese Ministry of Health and Welfare  large scale cooking facilities  more than 750 meals per day  more than 300 dishes of a single menu at a time  food saving  50 gram aliquots of each raw food material and cooked dish  more than 2 weeks, lower than -20 C

F. Kasuga 1 st Int Conf MRA Original purpose of food-storing system was to improve identification of vehicle food by microbiological examination.

F. Kasuga 1 st Int Conf MRA Food-storing system improvement of causative food identification Quantitative data (concentration in food) co-operation with laboratories Complete data set for Hazard Characterization Coordination Kitchen owners Health centers Prefectural laboratories cost supply epidemiological investigation facility and technique capacity cost supply Exposed Ill Food amount taken

F. Kasuga 1 st Int Conf MRA How do we combine those data?

F. Kasuga 1 st Int Conf MRA Outbreak reports Format, elements vary –Essential elements are required to be included. Rapid reports by FAX or s –Changeable, not confirmed Detail reports –Several months later Administrative reports in Japanese

F. Kasuga 1 st Int Conf MRA Outbreaks for which detail reports to MHLW are required (1) With more than 50 patients With less than 50 patients and with following characteristics –Death involved –Caused by imported food –Occurred in more than two prefectures by single source

F. Kasuga 1 st Int Conf MRA Outbreaks for which detail reports to MHLW are required (2) With less than 50 patients and with following characteristics (continued) –Unique epidemiology, or complicated investigation and actions needed –Caused by the following pathogens Yersinia enterocolitica O8 Campylobacter jejuni / coli Salmonella Enteritidis Enterohemorrhagic E. coli Clostridium botulinum

F. Kasuga 1 st Int Conf MRA Analysis of outbreak data (1989 – 1998) with Salmonella concentrations in implicated foods: In total 39 outbreak reports were collected, and they were divided into 5 categories upon settings.

F. Kasuga 1 st Int Conf MRA Outbreaks occurred at schools Ages of pupils in an elementary school are 6 to 12. Most schools serve the same lunch menu to all of their pupils on a single day. All the pupils in the school are reasonably considered to be the exposed population in those outbreaks. The exposed population to the contaminated food is usually very large

F. Kasuga 1 st Int Conf MRA Outbreaks occurred at schools

F. Kasuga 1 st Int Conf MRA Outbreaks occurred at schools

F. Kasuga 1 st Int Conf MRA Outbreaks occurred at daycare centers The age of children is less than 1 up to 6 years old. In general, the size of daycare population is smaller than that of schools and each daycare has its own kitchen in most places. Therefore the exposed populations were smaller than those of school cases. Attack rates were higher than those in school outbreaks, which might reflect the susceptibility of the population.

F. Kasuga 1 st Int Conf MRA Outbreaks occurred at daycare centers

F. Kasuga 1 st Int Conf MRA Hospital inpatients are generally considered to be more susceptible to pathogens than the healthy, normal population. The attack rates in collected outbreaks, however, were not very high. –the influence of concurrent medications including antibiotics?? Outbreaks occurred at hospitals

F. Kasuga 1 st Int Conf MRA Outbreaks occurred at hospitals

F. Kasuga 1 st Int Conf MRA Kitchens vary in size, the scale of outbreaks also differs. Amounts of ingested food were not always specified in the original reports, and assumptions were often made to estimate ingested dose of pathogens. The food storage conditions were also different among the outbreaks. Outbreaks occurred at restaurants, hotels, caterers, and other business kitchens (20 outbreaks)

F. Kasuga 1 st Int Conf MRA Outbreaks caused by confectionaries (6 outbreaks) Number of exposed people varies much in this group, from small outbreak with 5 cases to very large outbreak with more than one thousand.

F. Kasuga 1 st Int Conf MRA Comparison of dose-response from outbreaks where food samples were kept frozen or not - effect of freezing food system

F. Kasuga 1 st Int Conf MRA

F. Kasuga 1 st Int Conf MRA Outbreaks where food portions were stored frozen

F. Kasuga 1 st Int Conf MRA Outbreaks where food portions were not frozen

F. Kasuga 1 st Int Conf MRA Summary of my talk (1) Food-storing system Might be a good example of co-operation of management and assessment. Existing measures helped data collection for risk assessment. Very useful for developing dose-response models. Need to encourage local authorities to continue enumeration of causative microbes. –May need additional mechanism, cost supply.

F. Kasuga 1 st Int Conf MRA Summary of my talk (2) Outbreak reports Not always comprehensive, improvement of epidemiological investigation and report formatting needed. Case definition, recognition of foodborne outbreak is not systematically defined. –Underestimation of reported cases. Many outbreak reports are useful. Translating to English under discussion. Current summary to be available.

F. Kasuga 1 st Int Conf MRA Thank you! Co-workers: Masamitsu Hirota 1), Masamichi Wada 2), Toshihiko Yunokawa 3), Hajime Toyofuku 4), Masaki Shibatsuji 5), Hideshi Michino 5), Toshiaki Kuwasaki 5), Susumu Kumagai 6), Shigeki Yamamoto 1) 1) National Institute of Health Sciences 2) Nagano Research Institute for Health and Pollution 3) National Institute of Public Health 4) Food Safety Programme, World Health Organization 5) Ministry of Health, Labour and Welfare 6) The University of Tokyo Special advisors: Anna Lammerding, Aamir Fazil, Eric Ebel