CDC posts numbers on US outbreaks; chicken sickens the most
By News Desk on July 30, 2018 – Food Safety News
The federal Centers for Disease Control and Prevention is out with new data on outbreaks of foodborne illness, reporting statistics from 2009-2015 when outbreaks sickened more than 100,000 people.
Out of the 100,939 people who were confirmed with food poisoning from various pathogens during that time, 5,699 had to be admitted to hospitals and 145 died. In the outbreaks for which a specific food was determined to be the cause, chicken was responsible for the most illnesses, sickening 3,114 people, or about 12 percent of the total.
Researchers found pork and seeded vegetables were responsible for the second and third most illnesses. Pork sickened 2,670 people for about 10 percent of the total. Seeded vegetables sickened 2,572, also about 10 percent of the total.
The statistics are reported in Surveillance Summaries/July 27, 2018 / 67(10);1–11, published in the Morbidity and Mortality Weekly Report (MMWR) by Daniel Dewey-Mattia, MPH; Karunya Manikonda, MPH; Aron J. Hall, DVM; Matthew E. Wise, PhD; and Samuel J. Crowe, PhD (View author affiliations),
Researchers found that among the 2,953 outbreaks with a single confirmed etiology, four pathogens were most prominent:
1. Norovirus with 1,130 outbreaks, or 38 percent. The pathogen caused 27,623 illnesses, or 41 percent, of the outbreak-associated illnesses.
2. Salmonella caused 896 outbreaks, or 30 percent. The pathogen caused 23,662 illnesses, or 35 percent.
3. Outbreaks caused by Listeria, Salmonella, and Shiga toxin-producing Escherichia coli (STEC) were responsible for 82 percent of all hospitalizations and 82 percent of deaths reported.
Among 1,281 outbreaks in which the food reported could be classified into a single food category, the top three were:
1. Fish were the most commonly implicated category (222 outbreaks [17 percent]).
2. Dairy (136 [11 percent]).
3. Chicken (123 [10 percent]).
Multistate outbreaks comprised only 3 percent of all outbreaks reported, but accounted for 11 percent of illnesses, 34 percent of hospitalizations, and 54 percent 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 the 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.
Again, among 2,953 outbreaks with a single confirmed etiology, norovirus was the most common cause of outbreaks (1,130 outbreaks [38 percent]) and outbreak-associated illnesses (27,623 illnesses [41 percent]), followed by Salmonella with 896 outbreaks (30 percent) and 23,662 illnesses (35 percent).
Outbreaks caused by Listeria, Salmonella, and Shiga toxin-producing E. coli (STEC) were responsible for 82 percent of all hospitalizations and 82 percent 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 percent]), followed by dairy (136 [11 percent ]) and chicken (123 [10 percent]).
The food categories responsible for the most outbreak-associated illnesses were chicken (3,114 illnesses [12 percent]), pork (2,670 [10 percent]), and seeded vegetables (2,572 [10 percent]).
Location: A location of preparation was provided for 5,022 outbreak reports (87 percent), with 4,696 (94 percent) indicating a single location. Among outbreaks reporting a single location of preparation, restaurants were the most common location (2,880 outbreaks [61 percent]), followed by catering or banquet facilities (636 [14 percent]) and private homes (561 [12 percent]).
Sit-down dining style restaurants (2,239 [48 percent]) 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 percent]), catering or banquet facilities (18,141 [24 percent]), and institutions, such as schools (9,806 [13 percent]). The preparation location with the largest average number of illnesses per outbreak was institutions (46.5 percent), whereas restaurants had the smallest (11.6 percent).
Outbreaks: Outbreak investigators identified a food in 2,442 outbreaks (42 percent). These outbreaks resulted in 51,341 illnesses (51 percent). The food reported belonged to a single food category in 1,281 outbreaks (22 percent).
The food category most commonly implicated was fish (222 outbreaks [17 percent]), followed by dairy (136 [11 percent]) and chicken (123 [10 percent]). The food categories responsible for the most outbreak-associated illnesses were chicken (3,114 illnesses [12 percent]), pork (2,670 [10 percent]), and seeded vegetables (2,572 [10 percent]). A 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 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 were 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 percent of cases]).
An outbreak of Salmonella serotype Heidelberg infections attributed to chicken during 2013–2014 had the second most hospitalizations (200 [32 percent 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 percent 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 percent of cases) died.