Listeriosis is a kind of food poisoning. Food poisoning is caused by harmful germs in something you eat or drink. It can cause nausea, vomiting, diarrhea, fever and headache.
There are about 1,600 new cases of listeriosis each year in the United States. Most healthy people don’t get sick from listeriosis. It mostly affects people with a weak immune system, including newborns, elderly people and people with health conditions, like diabetes
Pregnant women are about 20 times more likely than others to get listeriosis. If you get listeriosis during pregnancy, it can cause serious and even life-threatening health problems for your growing baby.
Listeriosis is caused by bacteria called Listeria. Bacteria are tiny organisms that live in and around your body. Some bacteria are good for your body. Others, like Listeria, can make you sick. Listeria may be found in the soil, water, animals and animal poop.
Most people get listeriosis by eating food that is contaminated with Listeria. Food can come in contact with Listeria in soil, water, animals or animal poop.
Foods that may have Listeria include:
- Vegetables that come in contact with animal poop in the soil or in fertilizer
- Meats, including beef, pork and chicken
- Unpasteurized milk and foods made with it. If a food has been pasteurized, it’s been heated to kill bad germs. Milk and juices often are pasteurized. Look for the word “pasteurized” on the product label.
- Hot dogs (and juice from hot dogs) and deli meats, like ham, turkey, salami and bologna
- Pre-made or cold salads from delis or salad bars
- Pates or meat spreads that have been kept in a refrigerator. Canned meat spreads are safe.
- Soft cheeses, like feta, Brie, Camembert, Roquefort, blue-veined, queso blanco, queso fresco or Panela
- Smoked fish (nova style, lox, kippered or jerky) that has been kept in a refrigerator. Smoked fish is safe if it’s canned or you use it in a cooked dish (like a casserole).
Foods can cross contaminate each other. Cross contamination is the transfer of harmful bacteria from one thing to another. For example, if you use the same knife to cut raw chicken and tomatoes and don’t wash the knife in between, it can pass Listeria from the chicken to the tomatoes. Or if you get juice from a hot dog package on a knife, it can pass Listeria from the knife to the next food you cut.
You may hear news stories about foods that have been recalled (not allowed to be sold) because of listeriosis. If you’ve eaten one of these foods, call your health care provider right away.
Signs and symptoms of listeriosis usually start a few days after you’ve eaten infected food. But it can take up to 2 months for them to appear. To test for listeriosis, your provider takes a sample of your blood or urine, or fluid from your spine. Your provider sends the sample to a lab for testing.
Listeriosis usually causes mild, flu-like symptoms including:
- Muscle aches
If listeriosis infection spreads to your nervous system (brain and spinal cord), symptoms may include:
- Stiff neck
- Being confused
- Trouble with balance
Call your health care provider if you think you may have listeriosis. Treatment depends on your symptoms. During pregnancy, quick treatment with antibiotics can keep listeriosis from harming your baby. Antibiotics are medicines that kill infections caused by bacteria.
If you’re pregnant and get listeriosis, you can pass the infection to your baby. This can cause problems like:
- Miscarriage. This is when a baby dies in the womb before 20 weeks of pregnancy. Having listeriosis early in your pregnancy can increase your chances of having a miscarriage.
- Stillbirth. This is when a baby dies in the womb before birth, but after 20 weeks of pregnancy. Having listeriosis late in your pregnancy can increase your chances for stillbirth.
- Premature birth. This is birth that happens too early, before 37 completed weeks of pregnancy.
- Low birthweight. This is when a baby is born weighing less than 5 pounds, 8 ounces.
- Life-threatening infections in your baby. If you have listeriosis late in your pregnancy, your baby may be at risk for serious infections, like bacteremia (bacteria in the blood) and meningitis. Meningitis is an infection that causes swelling in the brain and spinal cord. Infected newborns may have health problems, including seizures, blindness and problems with the brain, heart and kidneys.
Here are some things you can to help prevent listeriosis:
- Handle foods safely when you wash, prepare, cook and store them.
- Wash your hands well with soap and water after contact with animals, animal food, bedding, tanks or animal poop.
- Wash your hands well with soap and water after using the bathroom.
- Watch out for cross contamination between yourself, food and any utensils or supplies you use when preparing or eating food.
Last reviewed March 2013
See also: Salmonellosis, Handling food safely, Eating healthy during pregnancy