Here’s a look at listeriosis, a serious infection generally caused by eating food contaminated with the bacterium Listeria monocytogenes.
2001 - Listeriosis (infection with L. monocytogenes) is added to the Centers for Disease Control and Prevention’s (CDC) list of nationally notifiable diseases.
Typically, Listeriosis affects older adults, pregnant women, infants and adults with compromised immune systems.
Pregnant women are approximately 10 times more likely to get listeriosis. Pregnant Hispanic women are 24 times more likely to get listeriosis than other people.
Listeria is named after Dr. Joseph Lister, an English surgeon who introduced sterilization into surgery. The mouthwash Listerine is also named after Dr. Lister.
Symptoms and Treatment
Symptoms include fever and muscle aches, and sometimes diarrhea or other gastrointestinal problems. Other symptoms are headache, confusion and convulsions.
Almost everyone diagnosed with listeriosis has an infection that has spread beyond the gastrointestinal tract.
Infections during pregnancy can lead to miscarriage, stillbirth, premature delivery or infection of the newborn.
Listeriosis can be treated with antibiotics.
Thoroughly cook meat.
Clean raw fruits and vegetables thoroughly before eating.
Keep uncooked meats and poultry separate from vegetables and from cooked foods.
Do not drink unpasteurized milk or eat foods that contain unpasteurized milk.
Wash hands, utensils and countertops after handling uncooked foods.
Recommendations for persons at high risk:
Do not eat hot dogs, cold cuts, other deli meats, or fermented or dry sausages unless they are cooked properly.
Do not eat refrigerated meat spreads and pâtés.
Do not eat soft cheese unless it is labeled as made with pasteurized milk.
Do not eat refrigerated smoked seafood, unless it is in a cooked dish or it is canned.
Timeline of selected US cases
Turkey Deli Meat - 2002
Multistate outbreak of L. monocytogenes associated with turkey deli meat.
September 18, 2002 - The CDC announces that it is investigating an outbreak of listeriosis infections.
October 12, 2002 - Pilgrim’s Pride Foods, in Franconia, Pennsylvania, recalls 27.4 million pounds of fresh and frozen ready-to-eat turkey and chicken products produced since May 1, 2002. In total, 54 illnesses, eight deaths, and three fetal deaths are reported in nine states.
Cantaloupe - 2011
Multistate outbreak of listeria associated with cantaloupes.
All the tainted cantaloupes were grown at Jensen Farms in Granada, Colorado. They were shipped to 17 states. Cases of listeriosis were reported in Alabama, Arkansas, California, Colorado, Illinois, Indiana, Kansas, Maryland, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, Texas, Virginia, West Virginia, Wisconsin and Wyoming. Health officials call it the deadliest food outbreak in the United States in nearly 100 years, and the third-deadliest outbreak in US history.
September 12, 2011 - The outbreak is announced by the CDC.
September 14, 2011 - The US Food and Drug Administration issues a press release to announce that Jensen Farms has issued a voluntary recall of its Rocky Ford-brand cantaloupes after being linked to a multistate outbreak of listeriosis. In total, 147 illnesses and 33 deaths are reported in 28 states.
September 26, 2013 - Eric and Ryan Jensen, brothers who own Jensen Farms, are taken into custody and charged with introducing tainted cantaloupe into interstate commerce.
October 22, 2013 -The Jensen brothers plead guilty to misdemeanor charges.
January 28, 2014 - They are sentenced to five years’ probation, including six months in home detention, for their role in the 2011 listeriosis outbreak.
Ricotta Cheese - 2012
September 10, 2012 - Multistate outbreak of listeriosis associated with Frescolina Marte Brand Ricotta Salata Cheese. Forever Cheese, Inc., initiates a voluntary recall of Frescolina Marte Brand Ricotta Salata Cheese with a single lot number. Four days later, Forever Cheese, Inc., expands the recall and removes all cheese related to the Italian exporter from the market.
In total, 22 illnesses and four deaths are reported in 13 states and the District of Columbia from the outbreak.
Caramel Apples - 2014
December 19, 2014 - The CDC announces it is investigating an outbreak of listeriosis linked to caramel apples.
January 6, 2015 - Bidart Bros. voluntarily recalls Granny Smith and Gala apples due to Listeria monocytogenes contamination at their apple-packing facility.
Blue Bell - 2015
March 13, 2015 - The CDC announces it is working with the FDA to investigate an outbreak of listeriosis linked to Blue Bell Ice Cream. Blue Bell removes its product “Scoops” from the market.
March 23, 2015 - Blue Bell announces the recall of 3 oz. institutional/food service ice cream cups.
April 3, 2015 - Blue Bell announces it has suspended operations at its Oklahoma plant.
April 20, 2015 - Blue Bell voluntarily recalls all of their products on the market.
June 10, 2015 - The CDC says that the investigation is over. In all, 10 people in four states were infected and hospitalized, and three people died.
Vulto Creamery - 2017
March 9, 2017 - The CDC announces it is working with the FDA to investigate an outbreak of listeriosis linked to soft raw milk cheese made by Vulto Creamery in Walton, New York. Vulto Creamery has recalled all lots of Ouleout, Miranda, Heinennellie and Willowemoc soft raw milk cheeses.
May 3, 2017 - The CDC announces that the outbreak appears to be over. In total, eight cases, including two deaths, were reported in four states - Connecticut, Florida, New York, and Vermont.
June 9, 2020 - The CDC announces that the outbreak appears to be over. In total, 36 cases, including four deaths, were reported in 17 states. Testing showed that enoki mushrooms supplied by the Korean company Green Co. Ltd. were likely the source of the outbreak.
Fresh Express - 2021
December 17, 2021 - The Michigan Department of Agriculture announces that it has identified Listeria monocytogenes in a sample from a Fresh Express packaged salad.
December 20, 2021 - Fresh Express recalls salad products produced at their Streamwood, Illinois facility.
December 22, 2021 - The CDC announces that it is working with the FDA to investigate a multistate outbreak of listeriosis linked to Fresh Express packaged salads. Ten people have been infected in eight states, with one death in Pennsylvania.
Dole - 2021
December 22, 2021 - The CDC announces that it has reopened a 2019 investigation into a multistate listeriosis outbreak linked to Dole packaged salads. Dole recalls packaged salads processed at facilities in North Carolina and Arizona.
January 7, 2021-February 1, 2022 - Dole recalls additional packaged salads containing iceberg lettuce processed at facilities in Ohio and California. Seventeen cases of listeriosis have been reported in 13 states, with two deaths in Michigan and Wisconsin.
Deli Meat and Cheese - 2022
November 9, 2022 - The CDC announces it is investigating a multistate Listeria outbreak linked to deli meat and cheese. Sixteens cases from six states – California, Illinois, Maryland, Massachusetts, New Jersey and New York – have been reported. One death and one pregnancy loss have also been reported in this outbreak. At least 13 people have been hospitalized, the agency said.
Timeline of selected cases outside the US
Canada - 2008
June 3, 2008 - The first known cases in the outbreak are reported in Ontario. The number of infections reported is unusually high.
June 17, 2008 - First death in the outbreak.
July 18, 2008 - Processed meat from Maple Leaf Foods is identified as the possible source of contamination.
July 2009 - A government-appointed, independent investigative report discloses 22 people died and 57 were infected in the outbreak.
Portugal - March 2009-February 2012
July 2010 - Health authorities launch a retrospective study after an increase in the number of cases reported, 16 months after the outbreak began.
February 2012 - The outbreak ends after 30 people were infected and 11 died. Cheese was identified as the probable cause.
Denmark - 2013-2014
September 2013 - The first cases are noted, according to the Danish research institute Statens Serum Institut.
August 2014 - There are 20 known cases. Danish authorities close down a meat producer near Copenhagen after linking the infection to one of its products, a rolled pork sausage.
November 2014 - The outbreak has caused 17 deaths among 41 people infected, Danish media reports.
European Union - 2015-2018
December 2015 - The first case is reported in the United Kingdom.
March 22, 2018 - The European Food Safety Authority says five European Union countries - Austria, Denmark, Finland, Sweden and the United Kingdom - have reported 32 cases of this strain of listeria, with six deaths. Frozen corn that was produced in Hungary and packaged in Poland is probably the cause.
South Africa - 2017-2018
January 2017 - The outbreak begins.
July 2017 - Doctors report an unusually high number of cases in babies to the National Institute of Communicative Diseases. As a result, a review of all cases is ordered.
December 2017 - The outbreak is confirmed. The Ministry of Health reports that 557 cases were reported in the year through November 29, with 36 deaths.
March 4, 2018 - The Health Ministry says 948 cases had been confirmed as of March 2, and 180 had died. Officials have identified a meat product known as “polony” from the Enterprise Food-Production facility in Polokwane in South Africa as the source of the outbreak.
March 5, 2018 - World Health Organization’s Peter K. Ben Embarek, who manages the WHO International Food Safety Authorities Network, tells Reuters that the outbreak is the largest ever recorded in the world.
October 31, 2018 - The National Institute for Communicable Diseases (NICD) confirms that the outbreak is over. From January 1, 2017, to July 17, 2018, there were 1,060 laboratory-confirmed listeriosis cases with 216 deaths.