This CDC report summarizes epidemiologic data for the 1,097 reported outbreaks occurring during 2007 (the most recent finalized data), which resulted in 21,244 cases of foodborne illness and 18 deaths.
Outbreaks – Single Etiologic Agent
Among the 497 outbreaks (12,767 illnesses) with a confirmed single etiologic agent, bacteria caused 259 (52%) outbreaks with 6,441 (50%) illnesses, viruses caused 199 (40%) outbreaks with 6,120 (48%) illnesses, chemical agents caused 34 (7%) outbreaks with 141 (1%) illnesses, and parasites caused five (1%) outbreaks with 65 (1%) illnesses.
Norovirus was the most common cause of illness, accounting for 193 (39%) of the confirmed single-etiology outbreaks and 97% of those caused by viruses.
Salmonella was the second most common, causing 136 (27%) confirmed single-etiology outbreaks and 53% of those attributed to bacteria. Among Salmonella serotypes identified, Enteritidis was the most common, causing 28 confirmed single-etiology outbreaks with 555 illnesses.
Shiga toxin-producing E. coli (STEC) caused 40 of the confirmed single-etiology outbreaks (15% of those attributed to bacteria), of which 39 were caused by serogroup O157.
Outbreak – Single Food Commodity
Among the 235 outbreaks attributed to a single food commodity, poultry (17%), beef (16%), and leafy vegetables (14%) were most often the cause of illness. Public health, regulatory, and agricultural professionals can use this information when creating targeted control strategies and to support efforts to promote safe food preparation practices among food employees and the public.
Outbreak – Unknown Etiology
Among the 363 outbreaks with an unknown etiology (5,122 illnesses), 257 outbreaks (71%) with 3,904 illnesses (76%) also had an unknown food vehicle. The most common reasons reported for not identifying an etiology or food vehicle were 1) delayed reporting of illnesses to the health department, 2) too many food items were consumed by ill persons to identify a single food as the contaminated vehicle, and 3) human or food sample test results were unavailable, either because samples could not be obtained or because tests were negative for the pathogens evaluated.
Outbreak – Multistate
Among the 18 multistate foodborne disease outbreaks (i.e., outbreaks in which exposure to the etiologic agent or agents occurred in more than one state), 10 were attributed to Salmonella, six to E. coli O157:H7, one to C. botulinum, and one to norovirus. Foods associated with multistate Salmonella outbreaks included commercially-processed frozen pot pies (401 illnesses, three deaths), commercially-processed vegetable snacks (87 illnesses), eggs (81 illnesses), spinach/lettuce (76 illnesses), beefsteak tomatoes (65 illnesses), raw tuna (44 illnesses), ground beef (43 illnesses), cheese (20 illnesses), alfalfa sprouts (15 illnesses), and raw fresh basil (11 illnesses). Of the six multistate outbreaks of E. coli O157:H7 infection, the vehicle for five was ground beef (117 illnesses) and the vehicle for one was commercially-processed frozen pepperoni pizzas (27 illnesses). The vehicle for the C. botulinum toxin outbreak (eight illnesses) was commercially canned hotdog chili sauce. The one multistate outbreak caused by norovirus was associated with raw oysters (40 illnesses).
Read full report – Surveillance of Foodborne Disease 2007