In Japan, strategies for ensuring food safety have been developed without reliable scientific evidence on the relationship between foodborne diseases and food sources. This study aimed to provide information on the proportions of foodborne diseases caused by seven major causative pathogens (Campylobacter spp., Salmonella, enterohemorrhagic Escherichia coli [EHEC], Vibrio parahaemolyticus, Clostridium perfringens, Staphylococcus aureus, and norovirus) attributed to foods and to explore factors affecting changes in these source attribution proportions over time using analysis of outbreak surveillance data. For the calculation of the number of outbreaks attributed to each source, simple-food outbreaks were assigned to the single-food category in question, and complex-food outbreaks were classified under each category proportional to the estimated probability. During 2007 to 2018, 8,730 outbreaks of foodborne diseases caused by seven pathogens were reported, of which 6,690 (76.6%) were of unknown source. We estimated the following source attribution proportions of foodborne diseases: chicken products (80.3%, 95% uncertainty interval [UI] 80.1 to 80.4) for Campylobacter spp.; beef products (50.1%, UI 47.0 to 51.5) and vegetables (42.3%, UI 40.9 to 45.5) for EHEC; eggs (34.6%, UI 27.8 to 41.4) and vegetables (34.4%, UI 27.8 to 40.8) for Salmonella; finfish (50.3%, UI 33.3 to 66.7) and shellfish (49.7%, UI 33.3 to 66.7) for V. parahaemolyticus; grains and beans (57.8%, UI 49.7 to 64.9) for S. aureus; vegetables (63.6%, UI 48.5 to 74.6), chicken products (12.7%, UI 4.6 to 21.5), and beef products (11.1%, UI 8.5 to 13.1) for C. perfringens; and shellfish (75.5%, UI 74.7 to 76.2) for norovirus. In this study, we provide the best available evidence-based information to evaluate the link between foodborne diseases and foods. Our results on source attribution for Campylobacter spp. and EHEC suggest that the strict health regulations for raw beef were reflected in the proportions of these diseases attributed to this food.

To investigate the epidemiological trait of gastroenteritis of human caused by Campylobacter jejuni, isolation of etiological agent was carried out. Isolated C. jejuni were biotyped and serotyped. A total of 1929 specimens from 438 human, 182 milking cows, 200 cattle, 187 goats, 70 dogs, 426 pigs, 278 chickens, 148 duck, 50 raw milk, 110 chicken meat, 20 duck liver and 50 river water was examined for the presence of C. jejuni and C. coli by direct plating and enrichment techniques. Isolation rates detected in human, animals food and water were as follows : human 0.7 %, ducks 54.7 %, dogs 37.1 %, chickens 33.7 %, goats 26.7 %, cattle 25.5 %, pigs 19.9 % and milking cows 7.7 %. The organism was isolated from 65 % of 20 duck livers and from 20 % of 110 chicken meat. Campylobacter was not recovered from raw milk and river water. The majority of the isolated 201 strains of C. jejuni was classified as biotype I (53.7 %) and Biotype II (36.8 %). 117 strains of C. coli were 59.8 % of biotype I, 40.1 % biotype II. Isolated C. jejuni strains showed 13 different serotype, and serotype 4, 5, 26 and 36 were most frequent. C. coli strains showed 7 different serotype, and serotype 21, 25 and 29 were relatively common