--- title: The Prevalence of Listeria in Food and the Environment date: 2012-07-12T15:38:00-07:00 author: admin canonical_url: "https://marlerclark.com/foodborne-illnesses/listeria/listeria-prevalence" section: Resource Library --- [Foodborne Illnesses](/foodborne-illnesses) / [Listeria](https://marlerclark.com/foodborne-illnesses/listeria) / # The Prevalence of Listeria in Food and the Environment ### *Listeria* bacteria are common in nature. *Listeria monocytogenes* is omnipresent in nature; it is found widely in such places as water, soil, infected animals, human and animal feces, raw and treated sewage, leafy vegetables, effluent from poultry and meat processing facilities, decaying corn and soybeans, improperly fermented silage, and raw (unpasteurized) milk. ![](https://s3.us-west-2.amazonaws.com/aboutlisteriacom-images/outbreaks/image3.jpeg)Foodborne listeriosis is relatively rare but is a serious disease with high fatality rates (20%–30%) compared with other food-borne microbial pathogens. Severe *L. monocytogenes* infections are responsible for high hospitalization rates (91%) among the most common food-borne pathogens, may cause sporadic cases or large outbreaks, and can persist in food-processing environments and multiply at refrigeration temperatures, making *L. monocytogenes* a significant public health concern. Foods commonly identified as sources of *Listeria* infection include improperly pasteurized fluid milk, cheeses (particularly soft-ripened varieties, such as traditional Mexican cheeses, Camembert, and ricotta), ice cream, raw vegetables, fermented raw-meat sausages, raw and cooked poultry, and cooked, ready-to-eat (RTE) sliced meats—often referred to as “deli meats.” One study found that, over a five-year period of testing, in multiple processing facilities, *Listeria* *monocytogenes* was isolated from 14% of 1,080 samples of smoked finfish and smoked shellfish. Ready-to-eat foods have been found to be a notable and consistent source of *Listeria*. For example, a research-study done by the *Listeria* Study Group found that *L. monocytogenes* grew from at least one food specimen in the refrigerators of 64% of persons with a confirmed *Listeria* infection (79 of 123 patients), and in 11% of more than 2,000 food specimens collected in the study. Moreover, 33% of refrigerators (26 of 79) contained foods that grew the same strain with which the individual had been infected, a frequency much higher than would be expected by chance. A widely cited U.S. Department of Agriculture (USDA) study that reviewed the available literature also summarized these findings: > In samples of uncooked meat and poultry from seven countries, up to 70 percent had detectable levels of *Listeria*. Schuchat et al. found that 32 percent of the 165 culture-confirmed listeriosis cases could be attributed to eating food purchased from store delicatessen counters or soft cheeses. In Pinner et al.’s microbiologic survey of refrigerated foods specimens obtained from households with listeriosis patients, 36 percent of the beef samples and 31 percent of the poultry samples were contaminated with *Listeria*. ![](https://s3.us-west-2.amazonaws.com/aboutlisteriacom-images/outbreaks/image4.jpeg)The prevalence of *Listeria* in ready-to-eat meats has not proven difficult to explain. As one expert in another much-cited article has noted: > The centralized production of prepared ready-to-eat food products. . . increases the risk of higher levels of contamination, since it requires that foods be stored for long periods at refrigerated temperatures that favor the growth of *Listeria*. During the preparation, transportation, and storage of prepared foods, the organism can multiply to reach a threshold needed to cause infection. The danger posed by the risk of *Listeria* in ready-to-eat meats prompted the USDA to declare the bacterium an adulterant in these kinds of meat products and, as a result, to adopt a zero-tolerance policy for the presence of this deadly pathogen. The Code of Federal Regulations includes requirements for the post-lethality control of *Listeria* in meat and poultry products. This regulation is referred to as “The *Listeria* Rule” and was enacted in 2003. The rule outlines prevention and control measures that must be taken in processing facilities to reduce the risk of contamination of ready-to-eat products. [ Next: Transmission of and Infection with Listeria › ](https://marlerclark.com/foodborne-illnesses/listeria/transmission-of-and-infection-with-listeria) ### More information about Listeria [August 23, 2023 ###### Listeria outbreak: Three die after drinking contaminated milkshakes Three people have died, and three others are in hospital after drinking milkshakes contaminated with listeria bacteria in the US state of Washington, health officials say. Marler Clark, the Listeria ... ](https://marlerclark.com/news_events/listeria-outbreak-three-die-after-drinking-contaminated-milkshakes) [July 12, 2023 ###### 2011 Listeria outbreaks linked to cantaloupes: A history A total of 148 persons infected with any of the five outbreak-associated strains of Listeria monocytogenes were reported to the CDC from 28 states. The number of infected persons identified ... ](https://marlerclark.com/news_events/2011-listeria-outbreak-linked-to-cantaloupes-a-history) [March 26, 2023 ###### Listeria linked to yogurt prompts recall Clio Snacks of Piscataway, New Jersey, is voluntarily recalling 581 cases of its Strawberry Granola & Greek Yogurt Parfait Bar due to potential contamination with Listeria monocytogenes, an organism which ... ](https://marlerclark.com/news_events/listeria-linked-to-yogurt-prompts-recall) [November 20, 2022 ###### Enoki Mushrooms recalled again As of November 15, 2022, two people infected with the outbreak strain of Listeria have been reported from two states. Sick people’s samples were collected from October 5, 2022, to October 8, 2022. ... ](https://marlerclark.com/news_events/enoki-mushrooms-recalled-again) [1. View all ](/news_events/outbreaks?illness=listeria&year=all) ## All Listeria Resources [###### Listeria Food Poisoning ](https://marlerclark.com/foodborne-illnesses/listeria/about-listeria) [###### The Incidence of Listeria Infections ](https://marlerclark.com/foodborne-illnesses/listeria/the-incidence-of-listeria-infections) [###### The Prevalence of Listeria in Food and the Environment ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-prevalence) [###### Transmission of and Infection with Listeria ](https://marlerclark.com/foodborne-illnesses/listeria/transmission-of-and-infection-with-listeria) [###### Who is Most at Risk of Becoming Ill with Listeria? ](https://marlerclark.com/foodborne-illnesses/listeria/who-is-most-at-risk-for-becoming-ill-with-listeria) [###### What Are the Symptoms of Listeria Infection? ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-symptoms-risks) [###### Complications of Listeria Infection ](https://marlerclark.com/foodborne-illnesses/listeria/complications-of-listeria-infection) [###### How is Listeria Infection Diagnosed? ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-diagnosis) [###### Treatment for Listeria Infection ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-treatment) [###### Antimicrobial Resistance in Bacteria ](https://marlerclark.com/foodborne-illnesses/listeria/antimicrobial-resistance-in-bacteria) [###### The Economic Impact of Listeria Infections ](https://marlerclark.com/foodborne-illnesses/listeria/the-economic-impact-of-listeria-infections) [###### Preventing Listeria Infection ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-prevention) [###### Listeria References ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-references) ### Other foodborne illnesses [E. coli](https://marlerclark.com/foodborne-illnesses/e-coli) [Salmonella](https://marlerclark.com/foodborne-illnesses/salmonella) [Hepatitis A](https://marlerclark.com/foodborne-illnesses/hepatitis-a) [Reactive Arthritis](https://marlerclark.com/foodborne-illnesses/reactive-arthritis) [Guillain-Barre Syndrome](https://marlerclark.com/foodborne-illnesses/guillain-barre-syndrome) [Irritable Bowel Syndrome](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome) [Norovirus](https://marlerclark.com/foodborne-illnesses/norovirus) [Botulism](https://marlerclark.com/foodborne-illnesses/botulism) [Campylobacter](https://marlerclark.com/foodborne-illnesses/campylobacter) [Shigella](https://marlerclark.com/foodborne-illnesses/shigella) [Cyclospora](https://marlerclark.com/foodborne-illnesses/cyclospora) [Hemolytic Uremic Syndrome](https://marlerclark.com/foodborne-illnesses/hemolytic-uremic-syndrome)