Foodborne outbreaks, Austria 2007

In 2007 Austria reported a total of 438 foodborne outbreaks affecting 1715 people, including 286 hospitalized patients and one death. Salmonella spp. and Campylobacter spp. accounted for 95% of all reported outbreaks. Forty-eight (11%) of the 438 Austrian outbreaks were acquired abroad. Of the 390 domestically acquired foodborne outbreaks, bacterial infection caused 376, viruses (norovirus and 1-time hepatitis A virus) caused 11, and intoxications (Staphylococcus aureus enterotoxins, alkaloid toxins) caused two. In one outbreak the causative agent was unknown. Salmonella spp. caused 264 (70%) of the bacterial outbreaks, Campylobacter spp. caused 104 (28%), enterohemorrhagic Escherichia coli (EHEC O145:H-, O157:H-, O157:H7, O182: H49, O91:H7, ONT:H4) caused six, Shigella flexneri and Shigella sonnei each caused two. The hospitalization rates were 22% for domestically acquired infections with Salmonella spp. and 14% for Campylobacter spp. Among outbreaks where the source was known, eggs were implicated in 49%, meat products (especially poultry) in 44% and fish in 2%. The ratio of household outbreaks to general outbreaks was 82.3% to 17.7%. In 54 of the 62 general domestic outbreaks the following locations of exposure were documented: commercial food suppliers (e.g. restaurants, cafeterias) 24 times, family celebrations, nursery schools, take-aways and barbecues 22 times, nursing homes and hospitals eight times. It is likely that the relatively high number of household outbreaks reflects an insufficient level of epidemiological investigation of outbreaks in Austria. More resources may be needed for identification of individual clusters that belong to larger foodborne outbreaks exceeding district or provincial borders.