Known pathogens cause an estimated 9.4 million foodborne illnesses annually in the United States (1). CDC collects data on foodborne disease outbreaks submitted by all states, the District of Columbia, and Puerto Rico through CDC’s Foodborne Disease Outbreak Surveillance System. Data reported for each outbreak include the number of illnesses, hospitalizations, and deaths; the etiologic agent; the implicated food vehicle; and other factors involved in food preparation and consumption.
During 2009–2010, a total of 1,527 foodborne disease outbreaks (675 in 2009 and 852 in 2010) were reported, resulting in 29,444 cases of illness, 1,184 hospitalizations, and 23 deaths. Among the 790 outbreaks with a single laboratory-confirmed etiologic agent, norovirus was the most commonly reported, accounting for 42% of outbreaks. Salmonella was second, accounting for 30% of outbreaks. Among the 299 outbreaks attributed to a food composed of ingredients from one of 17 predefined, mutually exclusive food commodities (2), those most often implicated were beef (13%), dairy (12%), fish (12%), and poultry (11%). The commodities in the 299 outbreaks associated with the most illnesses were eggs (27% of illnesses), beef (11%), and poultry (10%). Public health, regulatory, and food industry professionals can use this information when creating targeted control strategies along the farm-to-table continuum for specific agents, specific foods, and specific pairs of agents and foods. This information also supports efforts to promote safe food-handling practices among food workers and the public.
Of the 29,444 outbreak-related illnesses, 1,184 (4%) resulted in hospitalization. Salmonella caused the most outbreak-related hospitalizations with 583 (49%), followed by STEC with 190 (16%) and norovirus with 109 (9%). Outbreaks caused by Listeria resulted in the highest proportion of persons hospitalized (82%), followed by Clostridium botulinum (67%), and paralytic shellfish poisoning outbreaks (67%). Among the 23 deaths, 22 were attributed to bacterial etiologies (nine to Listeria monocytogenes, five Salmonella, four STEC O157, three Clostridium perfringens, and one Shigella), and one to norovirus.
A food vehicle was reported for 653 (43%) outbreaks; in 299 (46%) of these outbreaks the vehicle could be assigned to one of the 17 predefined commodities. The commodities most commonly implicated were beef, with 39 outbreaks (13%), followed by dairy and fish with 37 (13%) each, and poultry with 33 (11%). Among the 36 dairy-associated outbreaks for which pasteurization information was reported, 26 (81%) involved unpasteurized products. The commodities associated with the most outbreak-related illnesses were eggs with 2,231 illnesses (27%), beef with 928 (11%), and poultry with 826 (10%). The pathogen-commodity pairs responsible for the most outbreaks were Campylobacter in unpasteurized dairy (17 outbreaks), Salmonella in eggs and STEC O157 in beef (15 each), ciguatoxin in fish (12), and scombroid toxin (histamine fish poisoning) in fish (10). The pathogen-commodity pairs responsible for the most outbreak-related illnesses were Salmonella in eggs (2,231 illnesses), Salmonella in sprouts (493), and Salmonella in vine-stalk vegetables (422). The pathogen-commodity pairs responsible for the most hospitalizations were Salmonella in vine-stalk vegetables (88 hospitalizations), STEC O157 in beef (46), and Salmonella in sprouts (41). The pathogen-commodity pairs responsible for the most deaths were STEC O157 in beef (three deaths), and Salmonella in pork and Listeria in dairy (two each).
Thirty-eight multistate outbreaks were reported (16 in 2009 and 22 in 2010). Twenty-one were caused by Salmonella, 15 by STEC (13 O157, one O145, and one O26), and two by Listeria. The etiologic agent was isolated from an implicated food in 11 multistate outbreaks. Five of the multistate outbreaks were caused bySalmonella (in alfalfa sprouts [two outbreaks], ground turkey, shell eggs, and a frozen entrée [one each]). Six were caused by STEC (in ground beef [two outbreaks], unpasteurized Gouda cheese, multiple unpasteurized cheeses, hazelnuts, and cookie dough [one each]).
Among the 766 outbreaks with a known single setting where food was consumed, 48% were caused by food consumed in a restaurant or deli, and 21% were caused by food consumed in a private home. Forty-three outbreaks resulted in product recalls.†† The recalled foods were ground beef (eight outbreaks), sprouts (seven), cheese and cheese-containing products (six), oysters (five), raw milk (three), eggs (three), and salami (ground pepper), bison, sirloin steak, unpasteurized apple cider, cookie dough, frozen mamey fruit, hazelnuts, Romaine lettuce, ground turkey burger, tuna steak, and a frozen entrée (one each).