Commentary

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[Ann Emerg Med. 2010;55:49-50.]

Foodborne illness continues to be a significant cause of morbidity and mortality throughout the world. In the United States, 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths are estimated by the CDC each year.¹ Emergency physicians are one of the front-line providers encountering these illnesses. Therefore, it is important for emergency physicians to recognize foodborne illness, be knowledgeable about treatment, report suspected cases, and be aware of the changing epidemiology and emergence of new pathogens.

The incidence of foodborne illness, a term that includes both outbreaks and sporadic cases, has plateaued since 2004. Preliminary analysis of 2008 data from FoodNet shows no significant change in incidence of infection compared with data from 2005 to 2007. FoodNet, a part of the CDC's Emerging Infections Program that collects data from 10 states, routinely collects data on Campylobacter, Cryptosporidium, Cyclospora, Listeria, STEC, Salmonella, Shigella, Vibrio, and Yersinia. Overall, there has not been any significant decrease in rates of infection of these organisms since 2004. However, comparing the 2008 and 1996 to 1998 data, there has been a significant decrease in cases associated with all of the above organisms, with the exception of Cryptosporidium and Salmonella, which have remained constant.² Foodborne illness persists despite new control measures aimed at reducing food contamination.

An FBDO is defined as the occurrence of 2 or more cases of a similar illness resulting from the ingestion of a common food. Important parts of the history that lead to diagnosis and suspicion of an outbreak include incubation period, duration of illness, clinical symptoms, and whether others with similar exposure were affected. Other clues to the diagnosis may be obtained by asking the patients about their diet, such as whether they have consumed raw or undercooked food (eggs, meat, shellfish, fish), unpasteurized milk or juice, home-canned foods, fresh produce, or soft cheeses made from unpasteurized milk. Questions about other types of exposure may also be helpful, such as their occupation, farm and animal contact, daycare or long-term care, occupation, foreign travel, travel to coastal areas, camping trips, consumption of untreated water, and attendance at group picnics.³

The utility of stool cultures in the emergency department (ED) is controversial and not well studied. The yield of positive stool culture results has been estimated to be in the range of 1.5% to 5.8%, and the cost per positive result was estimated to be up to $1,200 in a 1980 study by Koplan et al.⁴ Additionally, having a positive culture result did not change treatment in 88.5% of ED patients with diarrhea in a 2003 study by Chan et al.⁵ Perhaps more important than guiding management of an individual case, stool cultures may be useful in identifying the cause of a foodborne outbreak. Emergency physicians can assist public health officials by properly reporting suspected foodborne outbreaks and sending appropriate diagnostic tests. As noted in the Morbidity and Mortality Weekly Report article, serotyping and other tests performed on culture specimens can be critical to determining the source.

Recently, a 2008 to 2009 multistate outbreak of Salmonella serotype typhimurium was traced to one Georgia plant that made peanut butter and peanut butter paste. This outbreak resulted in at least 714 cases of human illness in 46 states and led to one of the largest food product recalls in history.⁶ This outbreak was initially identified in 12 states as 13 Salmonella infections with a novel pulsed-field gel electrophoresis pattern, which prompted the CDC to begin an epidemiologic investigation. Failure to test or report these initial cases could have significantly delayed the investigation. This outbreak highlights the complexity of “ingredient-driven” outbreaks over broad geographic areas and the need for reporting suspected foodborne illness, rapid investigation by public health agencies, and the importance of surveillance systems.⁶

Per CDC guidelines, suspicion of foodborne outbreak should be reported when 2 or more patients present with symptoms that may have resulted from ingestion of a common food.³ Emergency physicians who suspect a foodborne illness should order appropriate testing, which usually includes stool cultures for diarrheal illness. If a reportable foodborne pathogen is found, typically the laboratory will report the case. Thus, emergency providers have an important responsibility in early outbreak identification and should be familiar with their local reporting system and laboratory testing protocols.

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References 

1. Mead PS, Slutsker L, Dietz V. Food-related illness and death in the United States. Emerg Infect Dis. 1999;5:607–625
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2. Centers for Disease Control and Prevention. Preliminary FoodNet data on the incidence of infection with pathogens commonly transmitted through food—10 states, 2008. MMWR Morb Mortal Wkly Rep. 2009;58:333–337
   • View In Article
3. Centers for Disease Control and Prevention. Diagnosis and management of foodborne illness: a primer for physicians and other health care professionals. MMWR Morb Mortal Wkly Rep. 2004;53:1–8
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4. Koplan JP, Fineberg HV, Ferraro MJB, et al. Value of stool cultures. Lancet. 1980;2:413–416
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5. Chan SSW, Ng KC, Lyon DJ, et al. Acute bacterial gastroenteritis: a study of adult patients with positive stool cultures treated in the emergency department. Emerg Med J. 2003;20:335–338
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6. Centers for Disease Control and Prevention. Multistate outbreak of Salmonella infections associated with peanut butter and peanut butter containing products—United States, 2008-2009. MMWR Morb Mortal Wkly Rep. 2009;58:1–6
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