- Listeria monocytogenes is a bacterial contaminant of food that can cause symptoms of food poisoning.
- Listeria can be found on many common foods such as deli meats, hot dogs, unpasteurized dairy products and cheeses, smoked seafood, and raw fruits and vegetables.
- People at high risk for serious Listeria illness include people with compromised immune systems, newborns, and the elderly.
- Symptoms of Listeria infection include fever, nausea and vomiting, diarrhea, abdominal pain and cramping, and back pain.
- Treatment for more severe cases of Listeria may include antibiotics.
- Food safety is key in preventing Listeria infection.
- Pregnant women should talk to their doctors about foods to avoid and proper food preparation and storage to avoid Listeria infection.
What is Listeria?
Listeria monocytogenes is a bacterial contaminant of food that can cause symptoms of food poisoning, termed listeriosis. Listeria commonly causes mainly gastrointestinal symptoms such as nausea, vomiting, and diarrhea but can also cause meningitis in severe cases.
Pregnant women can become sick with listeriosis and can pass the infection on to their fetus. This can cause birth defects or be fatal for the unborn child (miscarriage).
Listeria cases are often found in clusters or outbreaks because the source of the bacteria is related to contaminated food products. Recent outbreaks of Listeria include cheese products, broccoli salad, and cantaloupes.
What causes listeriosis (Listeria infection)?
Listeriosis is caused by the bacteria Listeria monocytogenes. When the bacteria are ingested after eating contaminated foods, symptoms of the illness can occur. The bacteria are able to enter into GI tract cells without disrupting the cells. The bacteria multiply and then leave the GI cell and are picked up by macrophage cells. This allows the bacteria to initially avoid the body's immune defenses.
Listeria can be found on and in many common foods such as deli meats, hot dogs, unpasteurized dairy products and cheeses, smoked seafood, and raw fruits and vegetables. It can also be found in contaminated water primarily in tropical areas. Recreation exposure and infection can occur through swimming, boating, or canoeing in such contaminated water.
What are risk factors for a Listeria infection?
Anyone can get an infection with Listeria. Most healthy people have mild gastrointestinal symptoms.
There are some groups of people who are at higher risk for more serious illness from Listeria, including
- people with compromised immune systems,
- the elderly.
What is the incubation period for a Listeria infection?
The incubation period (which is the time from infection with the bacteria to the onset of symptoms) for a Listeria infection typically ranges from five to 14 days.
Gelfand, Michael S. "Clinical Manifestations and Diagnosis of Listeria monocytogenes Infection." UpToDate.com. Nov. 2014. <http://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-listeria-monocytogenes-infection?source=search_result&search=Listeriosis&selectedTitle=1~130>.
Gelfand, Michael S. "Treatment, Prognosis, and Prevention of Listeria monocytogenes Infection." UpToDate.com. Nov. 2014. <http://www.uptodate.com/contents/treatment-prognosis-and-prevention-of-listeria-monocytogenes-infection?source=search_result&search=Listeriosis&selectedTitle=2~130>.
United States. Centers for Disease Control and Prevention. "Listeria (Listeriosis)." July 31, 2014. <http://www.cdc.gov/listeria/outbreaks/cheese-02-14/index.html>.
United States. Centers for Disease Control and Prevention. "Multistate Outbreak of Listeriosis Linked to Whole Cantaloupes from Jensen Farms, Colorado." Aug. 27, 2012. <http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/index.html>.
United States. "Listeria." Foodsafety.gov. <http://www.foodsafety.gov/poisoning/causes/bacteriaviruses/listeria/>.