Foodborne Agents Identified in US Outbreaks

US - A total of 1,097 foodborne disease outbreaks were reported in 2007 to the Centers for Disease Control and Prevention, according to a CDC analysis. State investigators reported 21,244 illnesses and 18 deaths as a result of these outbreaks. The report also provides the most recent data on how many illnesses were linked to specific types of foods.

16 August 2010

3 minute read

North America

"Knowing more about what types of foods and foodborne agents have caused outbreaks can help guide public health and the food industry in developing measures to effectively control and prevent infections and help people stay healthy," said Chris Braden, acting director of the CDC's Division of Foodborne, Waterborne and Environmental Diseases.

Despite health officials' efforts, the cause of an outbreak – either the food or the foodborne agent responsible – often cannot be determined or confirmed. This most commonly is the case when the outbreak is small. Of 1,097 reported outbreaks in 2007, 497 (or 45 per cent) confirmed that one foodborne agent was responsible and in an additional 12 outbreaks more than one foodborne agent was responsible. Thus, in more than half of the outbreaks, a foodborne agent was not identified. Norovirus was the most frequently confirmed foodborne agent (39 per cent), followed by Salmonella (27 per cent).

Foodborne disease outbreaks due to norovirus occur most often when infected food handlers do not wash their hands well after using the toilet; outbreaks due to salmonella occur most often when foods are contaminated with animal feces. Contaminated foods are often of animal origin, such as beef, poultry, milk or eggs. But any food, including vegetables, may become contaminated. Thorough cooking kills Salmonella.

The report states that in the 235 outbreaks where one food commodity was identified, the largest number of illnesses listed poultry (691 illnesses), beef (667 illnesses), and leafy vegetables (590 illnesses) as the cause. The CDC tracks 17 food commodity categories.

To prevent foodborne illnesses, CDC recommends that consumers and food handlers appropriately clean, separate, cook and chill foods.

The full report, Surveillance for Foodborne Disease Outbreaks — United States, 2007 appears in last week's edition of CDC's Morbidity and Mortality Weekly Report, and is available online at www.cdc.gov/mmwr.