FOOD-BUG
Infections caused by food-borne bacteria – retrospective study on association of morbidity and mortality of Finns, prospective study on tracing of domestic cases and risk assessment
Consortium Leader: Research Professor Anja Siitonen, National Public Health Institute (KTL), Department of Bacterial and Inflammatory Diseases, Enteric Bacteria Laboratory (www.ktl.fi)
Other group leaders:
MD, PhD Markku Kuusi, National Public Health Institute (KTL), Department of Infectious Disease Epidemiology (www.ktl.fi)
Professor Sinikka Pelkonen, Finnish Food Safety Authority (Evira), Kuopio (www.evira.fi)
DVM Pirkko Tuominen, Finnish Food Safety Authority (Evira), Department of Risk Assessment, Helsinki (www.evira.fi)
Other persons involved in the project:
PhD (Microbiologist) Kaisa Haukka, National Public Health Institute (KTL), Department of Bacterial and Inflammatory Diseases, Enteric Bacteria Laboratory
DVM, PhD Ruska Rimhanen-Finne, National Public Health Institute (KTL), Department of Infectious Disease Epidemiology
RN Sari Jaakola, Kansanterveyslaitos, National Public Health Institute (KTL), Department of Infectious Disease Epidemiology
MSc (Biostatistician) Mikko Virtanen Kansanterveyslaitos, Infektioepidemiologian osasto
PhD (Mathematician) Jukka Ranta, Finnish Food Safety Authority (Evira), Department of Risk Assessment, Helsinki
DVM Henry Kuronen, Finnish Food Safety Authority (Evira), Kuopio
DVM Tarja Pohjanvirta, Finnish Food Safety Authority (Evira), Kuopio
Researcher Sirpa Heinikainen, Finnish Food Safety Authority (Evira), Kuopio
ABSTRACT
Food safety and microbiological quality are important public health topics. Salmonella-bacteria belong to the most commonly reported food-borne pathogens and enterohaemorrhagic Escherichia coli (EHEC) is one of the most dangerous foodborne pathogens. In this project, we study the risks of food-borne bacteria to public health in general as well as trace and characterize Salmonella and EHEC strains in particular. The project has three parts: 1) a retrospective registry-based study, 2) a prospective real-time surveillance and population-based study and 3) risk assessment.
The retrospective study will determine the morbidity and mortality associated with food-borne bacterial gastrointestinal infections in Finland since 1995. The bacteria included in the registry-based study will be Salmonella, Campylobacter, Shigella, Yersinia and EHEC.
The prospective study will concentrate on real-time tracing the source and transmission routes of domestic food-borne Salmonella and EHEC infections and includes also the case-control study. The properties of the human isolates are compared with those of the isolates obtained from the animal and food sources. Also suspected foodstuffs will be sampled more rigorously. Thus, the most common sources and transmission routes of the pathogens should be revealed. The endemic Salmonella Typhimurium definite phage type DT1 causing yearly peaks of infections and antimicrobial resistant strains will gain special attention.
More accurate real-time tracing of sporadic food-borne infections enables also better containment of emerging epidemics. Furthermore, the evolutionary studies give us a chance to predict the development of such important traits in pathogens as various virulence-associated characteristics and antimicrobial resistance.
Finally, a new method for risk assessment will be created based on a quantitative mathematical model. The model will combine the results obtained with the novel laboratory techniques together with data from the National Register on Infectious Diseases, food-borne outbreaks and food production assessing the consumer exposure and estimating the total risk of a Finnish consumer to get Salmonella or EHEC from food available in Finland. Knowing the true impact of the food-borne infections in the past will give us a chance to assess the effect and cost-benefits of possible new precautionary actions for the public health. The results of the project can be utilized by the industry and food authorities as well as by the health care officials. The method to be developed will be applicable also to the assessment of other food-borne pathogens.
Key words: food-borne bacteria, Salmonella, EHEC, registry-based study, case-control-study, characterization and tracing of bacterial strains, risk assessment, exposure assessment, risk estimate