Fast Facts of CDC: Surveillance for Foodborne Disease Outbreaks — United States, 2009–2015 Surveillance Summaries / July 27, 2018 / 67(10);1–11:

2009–2015: 5,760 outbreaks that resulted in 100,939 illnesses, 5,699 hospitalizations, and 145 deaths.

Among 2,953 outbreaks with a single confirmed etiology:

  1. Norovirus was the most common cause of outbreaks (1,130 outbreaks [38%]) and outbreak-associated illnesses (27,623 illnesses [41%]).
  2. Salmonella with 896 outbreaks (30%) and 23,662 illnesses (35%).
  3. Outbreaks caused by ListeriaSalmonella, and Shiga toxin-producing Escherichia coli (STEC) were responsible for 82% of all hospitalizations and 82% of deaths reported.

Among 1,281 outbreaks in which the food reported could be classified into a single food category:

  1. Fish were the most commonly implicated category (222 outbreaks [17%]).
  2. Dairy (136 [11%]).
  3. Chicken (123 [10%]).

The food categories responsible for the most outbreak-associated illnesses were:

  1. Chicken (3,114 illnesses [12%]).
  2. Pork (2,670 [10%]).
  3. Seeded vegetables (2,572 [10%]).

Multistate outbreaks comprised only 3% of all outbreaks reported but accounted for 11% of illnesses, 34% of hospitalizations, and 54% of deaths.

Problem/Condition: Known foodborne disease agents are estimated to cause approximately 9.4 million illnesses each year in the United States. Although only a small subset of illnesses are associated with recognized outbreaks, data from outbreak investigations provide insight into the foods and pathogens that cause illnesses and the settings and conditions in which they occur.

Description of System: The Foodborne Disease Outbreak Surveillance System (FDOSS) collects data on foodborne disease outbreaks, which are defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food. Since the early 1960s, foodborne outbreaks have been reported voluntarily to CDC by state, local, and territorial health departments using a standard form. Beginning in 2009, FDOSS reporting was made through the National Outbreak Reporting System, a web-based platform launched that year.

Results: During 2009–2015, FDOSS received reports of 5,760 outbreaks that resulted in 100,939 illnesses, 5,699 hospitalizations, and 145 deaths. All 50 states, the District of Columbia, Puerto Rico, and CDC reported outbreaks. Among 2,953 outbreaks with a single confirmed etiology, norovirus was the most common cause of outbreaks (1,130 outbreaks [38%]) and outbreak-associated illnesses (27,623 illnesses [41%]), followed by Salmonella with 896 outbreaks (30%) and 23,662 illnesses (35%). Outbreaks caused by ListeriaSalmonella, and Shiga toxin-producing Escherichia coli (STEC) were responsible for 82% of all hospitalizations and 82% of deaths reported. Among 1,281 outbreaks in which the food reported could be classified into a single food category, fish were the most commonly implicated category (222 outbreaks [17%]), followed by dairy (136 [11%]) and chicken (123 [10%]). The food categories responsible for the most outbreak-associated illnesses were chicken (3,114 illnesses [12%]), pork (2,670 [10%]), and seeded vegetables (2,572 [10%]). Multistate outbreaks comprised only 3% of all outbreaks reported but accounted for 11% of illnesses, 34% of hospitalizations, and 54% of deaths.

Location: A location of preparation was provided for 5,022 outbreak reports (87%), with 4,696 (94%) indicating a single location. Among outbreaks reporting a single location of preparation, restaurants were the most common location (2,880 outbreaks [61%]), followed by catering or banquet facilities (636 [14%]) and private homes (561 [12%]). Sit-down dining style restaurants (2,239 [48%]) were the most commonly reported type of restaurant. The locations of food preparation with the most outbreak-associated illnesses were restaurants (33,465 illnesses [43%]), catering or banquet facilities (18,141 [24%]), and institutions, such as schools (9,806 [13%]). The preparation location with the largest average number of illnesses per outbreak was institutions (46.5), whereas restaurants had the smallest (11.6).

Outbreaks: Outbreak investigators identified a food in 2,442 outbreaks (42%). These outbreaks resulted in 51,341 illnesses (51%). The food reported belonged to a single food category in 1,281 outbreaks (22%). The food category most commonly implicated was fish (222 outbreaks [17%]), followed by dairy (136 [11%]) and chicken (123 [10%]). The food categories responsible for the most outbreak-associated illnesses were chicken (3,114 illnesses [12%]), pork (2,670 [10%]), and seeded vegetables (2,572 [10%]). Scombroid toxin in fish was the single confirmed etiology and food category pair responsible for the most outbreaks (85), followed by ciguatoxin in fish (72) and Campylobacter in dairy (60). The pathogen-food category pairs that caused the most outbreak-associated illnesses were Salmonella in eggs (2,422 illnesses), Salmonella in seeded vegetables (2,203), and Salmonella in chicken (1,941). In comparison, scombroid toxin and ciguatoxin outbreaks from fish resulted in 519 outbreak-associated illnesses, an average of three illnesses per outbreak. Outbreaks of Salmonella infections from seeded vegetables resulted in an average of 88 illnesses per outbreak, and outbreaks of Salmonella infections from eggs resulted in an average of 78 illnesses per outbreak.

Food Implicated: Several novel food vehicles caused outbreaks during the study period. In 2011, an outbreak of Salmonella serotype Enteritidis infections linked to pine nuts imported from Turkey resulted in 53 illnesses and two hospitalizations. In 2014, an outbreak of Salmonella serotypes Gaminara, Hartford, and Oranienburg in chia seed powder imported from Canada caused 45 illnesses and seven hospitalizations. An outbreak of STEC serogroups O26 and O121 infections that began in 2015 was linked to raw wheat flour produced in the United States; it resulted in 56 illnesses and 16 hospitalizations in 24 states. An outbreak of Salmonella serotype Virchow infections attributable to moringa leaf powder imported from South Africa began in 2015 and caused 35 illnesses and six hospitalizations in 24 states. It was an ingredient of an organic powdered shake mix branded to be used as a meal replacement.

Multistate Outbreaks: Multistate outbreaks comprised only 3% of outbreaks but were responsible for 11% of illnesses, 34% of hospitalizations, and 54% of deaths. Multistate outbreaks involved a median of seven states with a range of two to 45 states in which exposure occurred. The largest of the 177 multistate outbreaks was caused by Salmonella serotype Enteritidis and due to contaminated shell eggs. An estimated 1,939 persons were infected in 10 states beginning in 2010. An outbreak of Salmonella serotype Poona infections attributed to cucumbers in 2015 had the second highest number of illnesses (907 illnesses in 40 states). This outbreak also had the most outbreak-associated hospitalizations (204 [22% of cases]). An outbreak of Salmonella serotype Heidelberg infections attributed to chicken during 2013–2014 had the second most hospitalizations (200 [32% of cases]) and involved persons from 29 states and Puerto Rico. An outbreak of Listeria monocytogenes infections attributed to cantaloupes in 28 states in 2011 had the most deaths (33 [22% of cases]), followed in 2014 by an outbreak in 12 states of Listeria monocytogenes infections attributed to caramel apples, another novel food vehicle (9), in which seven persons (20% of cases) died.

Daniel Dewey-Mattia, MPH; Karunya Manikonda, MPH; Aron J. Hall, DVM; Matthew E. Wise, PhD; Samuel J. Crowe, PhD.

  1. CDC Annual summaries of foodborne outbreaks. Atlanta, GA: US Department of Health and Human Services, CDC; 2018. https://www.cdc.gov/fdoss/annual-reports/index.html
  2. Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis 2011;17:7–15. CrossRefPubMed
  3. National Notifiable Diseases Surveillance System (NNDSS). Foodborne disease outbreak 2011 case definition. Atlanta, GA: US Department of Health and Human Services, CDC; 2013. http://wwwn.cdc.gov/nndss/conditions/foodborne-disease-outbreak/case-definition/2011
  4. PulseNet. Atlanta, GA: US Department of Health and Human Services, CDC; 2017. https://www.cdc.gov/pulsenet/index.html
  5. Guide to confirming an etiology in foodborne disease outbreak. Atlanta, GA: US Department of Health and Human Services, CDC; 2015. https://www.cdc.gov/foodsafety/outbreaks/investigating-outbreaks/confirming_diagnosis.html
  6. Interagency Food Safety Analytics Collaboration (IFSAC) Food Categorization Scheme. Atlanta, GA: US Department of Health and Human Services, CDC; 2015. https://www.cdc.gov/foodsafety/ifsac/projects/food-categorization-scheme.html
  7. Richardson LC, Bazaco MC, Parker CC, et al. An updated scheme for categorizing foods implicated in foodborne disease outbreaks: a tri-agency collaboration. Foodborne Pathog Dis 2017;14:701–10. CrossRefPubMed
  8. US Census Bureau. Population and housing unit estimates. Washington, DC: US Department of Commerce, US Census Bureau; 2016. https://www.census.gov/programs-surveys/popest.html
  9. Angelo KM, Conrad AR, Saupe A, et al. Multistate outbreak of Listeria monocytogenesinfections linked to whole apples used in commercially produced, prepackaged caramel apples: United States, 2014–2015. Epidemiol Infect 2017;145:848–56. CrossRef PubMed
  10. Gould LH, Kline J, Monahan C, Vierk K. Outbreaks of disease associated with food imported into the United States, 1996–2014. Emerg Infect Dis 2017;23:525–8. CrossRefPubMed
  11. Gould LH, Walsh KA, Vieira AR, et al. . Surveillance for foodborne disease outbreaks—United States, 1998–2008. MMWR Surveill Summ 2013;62(No. SS-2):1–34. PubMed
  12. Hall AJ, Wikswo ME, Pringle K, Gould LH, Parashar UD. Vital signs: foodborne norovirus outbreaks—United States, 2009–2012. MMWR Morb Mortal Wkly Rep 2014;63:491–5. PubMed
  13. Food and Drug Administration. Food Code 2017. Silver Spring, MD: US Department of Health and Human Services, Food and Drug Administration; 2018. https://www.fda.gov/Food/GuidanceRegulation/RetailFoodProtection/FoodCode/ucm595139.htm
  14. Tauxe RV. Emerging foodborne diseases: an evolving public health challenge. Emerg Infect Dis 1997;3:425–34. CrossRefPubMed
  15. Food and Drug Administration. Egg safety final rule. Silver Spring, MD: US Department of Health and Human Services, Food and Drug Administration; 2017. http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/Eggs/ucm170615.htm
  16. Food and Drug Administration. FDA Food Safety Modernization Act (FSMA). Silver Spring, MD: US Department of Health and Human Services, Food and Drug Administration; 2017. https://www.fda.gov/Food/GuidanceRegulation/FSMA
  17. Food Safety and Inspection Service. Salmonella action plan. Washington, DC: US Department of Agriculture, Food Safety and Inspection Service; 2015. https://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/foodborne-illness-and-disease/salmonella/sap