Listeria is a kind of bacteria that is found in soil, water, and some animals, including cattle and poultry. When eaten, Listeria causes a foodborne illness called listeriosis. Listeriosis is one of the most serious types of food poisoning.
Listeriosis can cause mild, flu-like symptoms such as fever, chills, muscle aches, and diarrhea or upset stomach. You also may have a stiff neck, headache, confusion, or loss of balance. Symptoms may appear as late as 2 months after you have eaten something with Listeria. Many pregnant women do not have any symptoms. Even if you do not feel sick, you can pass the infection to your fetus.
Pregnant women are 10 times more likely to get listeriosis than the general population. Vomiting and diarrhea can cause the body to lose too much water. This is called dehydration. Listeriosis also can cause miscarriage, stillbirth, or preterm labor.
Babies born with listeriosis may have serious infections of the blood or brain. Listeriosis can cause lifelong health problems for your baby, including intellectual disability, paralysis, seizures, blindness, or problems with the brain, kidneys, or heart. Listeriosis also can cause death in newborns.
If you think you have eaten food contaminated with Listeria or if you have any of the symptoms of listeriosis, contact your obstetrician–gynecologist (ob-gyn) or other health care professional right away. Remember that it can take 2 months for symptoms to appear.
Your ob-gyn or other health care professional may give you a blood test to see if you have listeriosis. You may need to take antibiotics to treat the infection and prevent your fetus from becoming infected.
To help prevent listeriosis, avoid eating the following foods while you are pregnant:
Unpasteurized milk and foods made with unpasteurized milk, including soft cheeses
Hot dogs and luncheon meats, unless they are heated until steaming hot just before serving
Refrigerated pâté and meat spreads
Refrigerated smoked seafood
Unwashed raw produce such as fruits and vegetables
Avoid all raw and undercooked seafood, eggs, meat, and poultry while you are pregnant. Do not eat sushi made with raw fish (cooked sushi is safe). Cooking and pasteurization are the only ways to kill Listeria.
Follow these steps for food safety:
Wash your hands for at least 20 seconds before and after touching raw food, and after using the bathroom, changing diapers, or touching an animal.
Rinse all raw produce thoroughly under running water before eating, peeling, cutting, or cooking.
Do not rinse raw meat or poultry before cooking. That can spread bacteria to other kitchen surfaces.
Keep your kitchen clean. Wash your utensils, countertops, and cutting boards with soap and hot water after using them.
Keep raw meat, poultry, eggs, seafood, and their juices away from other food.
Use a separate cutting board for raw meat, poultry, and seafood.
Do not put cooked food on a plate that also held raw food, unless the plate was washed.
Do not put cooked food in the same sauce that was used to marinate raw food, unless the sauce is boiled first.
Use a food thermometer to check that meat, poultry, seafood, and eggs are at a safe temperature.
Place the food thermometer in the thickest part of the food, away from bone, fat, and gristle.
Cover, stir, and rotate food in a microwave to cook the food evenly. Allow for standing time before using a food thermometer.
Keep your refrigerator at 40°F or below and your freezer at 0°F or below.
Thaw food in a refrigerator, microwave, or cold water. Cook food immediately after thawing in a microwave or cold water.
Meat and poultry thawed in the refrigerator may be refrozen before or after cooking. If thawed in a microwave or cold water, cook before refreezing.
Do not leave perishable food at room temperature for more than 2 hours (1 hour when the outside temperature is above 90°F).
Only buy eggs that are refrigerated. Store eggs in the refrigerator in their original carton and use within 3–5 weeks.
Only buy precut produce that is refrigerated or surrounded by ice. Keep precut produce refrigerated at home.
Antibiotics: Drugs that treat certain types of infections.
Fetus: The stage of human development beyond 8 completed weeks after fertilization.
Listeriosis: A type of illness you can get from bacteria found in unpasteurized milk, hot dogs, luncheon meats, and smoked seafood.
Miscarriage: Loss of a pregnancy that is in the uterus.
Obstetrician–Gynecologist (Ob-Gyn): A doctor with special training and education in women’s health.
Pasteurization: The process of heating certain foods to a specific temperature for a set period of time to kill harmful bacteria.
Preterm: Less than 37 weeks of pregnancy.
Stillbirth: Birth of a dead fetus.
Don't have an ob-gyn? Search for doctors near you.
FAQ501 Published: June 2018 Last reviewed: August 2022
Copyright 2022 by the American College of Obstetricians and Gynecologists. All rights reserved. Read copyright and permissions information.
This information is designed as an educational aid for the public. It offers current information and opinions related to women's health. It is not intended as a statement of the standard of care. It does not explain all of the proper treatments or methods of care. It is not a substitute for the advice of a physician. Read ACOG’s complete disclaimer.
Listeria from Food Safety for Moms to Be
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What Is Foodborne Illness? | Listeria | Toxoplasma
Listeria: Frequently Asked Questions
"What is Listeria monocytogenes?"
It's a harmful bacterium that can be found in refrigerated, ready-to-eat foods (meat, poultry, seafood, and dairy - unpasteurized milk and milk products or foods made with unpasteurized milk), and produce harvested from soil contaminated with L. monocytogenes. Many animals can carry this bacterium without appearing ill, and thus, it can be found in foods made from animals. L. monocytogenes is unusual because it can grow at refrigerator temperatures where most other foodborne bacteria do not. When eaten, it may cause listeriosis, an illness to which pregnant women and their unborn children are very susceptible.
"How could I get listeriosis?"
By eating ready-to-eat meats, poultry, seafood, and dairy products that are contaminated with L. monocytogenes. You can also get listeriosis by eating contaminated foods processed or packaged in unsanitary conditions or by eating fruits and vegetables that are contaminated from the soil or from manure used as fertilizer.
"How could listeriosis affect me?"
The symptoms can take a few days or even weeks to appear and may include fever, chills, muscle aches, diarrhea or upset stomach, headache, stiff neck, confusion, and loss of balance. In more serious cases, listeriosis could also lead to the mother's death.
Most of the time, pregnant women who are infected with listeriosis don't feel sick. However, they can pass the infection to their unborn babies without even knowing it. That's why prevention of listeriosis is very important. In any case, if you experience any of the above symptoms, see your doctor or healthcare provider immediately.
Pregnant women are about 10 times more likely to get listeriosis than other healthy adults.
An estimated 1/6 of all Listeria cases occur in pregnant women.
(Centers for Disease Control and Prevention)
"How could listeriosis affect my baby?"
During the first trimester of pregnancy, listeriosis may cause miscarriage. As the pregnancy progresses to third trimester, the mother is more at risk. Listeriosis can also lead to premature labor, the delivery of a low-birth-weight infant, or infant death. Fetuses who have a late infection may develop a wide range of health problems, including intellectual disability, paralysis, seizures, blindness, or impairments of the brain, heart, or kidney. In newborns, L. monocytogenes can cause blood infections and meningitis.
Listeriosis & Pregnant Hispanic Women
Studies show that pregnant Hispanic women may have a higher incidence of listeriosis than pregnant non-Hispanic women. This is most likely because they might make and eat homemade soft cheese and other traditional foods made from unpasteurized milk. "Queso fresco"- a traditional homemade cheese, prepared from unpasteurized milk and widely consumed by Hispanics - has led to miscarriages, death of newborns, and premature delivery caused by L. monocytogenes.
To prevent the risk of listeriosis, Hispanic pregnant women should not eat homemade soft cheeses and other traditional foods made from unpasteurized milk. Like all other pregnant women, they should follow the food safety precautions outlined below.
"How can I prevent listeriosis?"
The good news is that listeriosis can be prevented! Here's how...
Time to Chill
Your refrigerator should register at 40° F (4° C) or below and the freezer at 0° F (-18° C). Place a refrigerator thermometer in the refrigerator, and check the temperature periodically. During the automatic defrost cycle, the temperature may temporarily register slightly higher than 40° F. This is okay.
Refrigerate or freeze perishables, prepared food, and leftovers within two hours of eating or preparation. Follow the 2-Hour Rule: Discard food that's left out at room temperature for longer than 2 hours. When temperatures are above 90° F (32° C), discard food after 1 hour.
Use ready-to-eat, perishable foods, such as dairy, meat, poultry, seafood, and produce, as soon as possible.
Clean your refrigerator regularly.
Wipe up spills immediately.
Clean the inside walls and shelves with hot water and a mild liquid dishwashing detergent; then rinse.
Once a week, check expiration and "use by" dates, and throw out foods if the date has passed. Follow the recommended storage times for foods.
Refrigerator & Freezer Storage Chart (PDF).
To Eat or Not to Eat?
Hot dogs, deli meats, and luncheon meats - unless they're reheated until steaming hot.
Soft cheeses like Feta, Brie, and Camembert, "blue-veined cheeses," or "queso blanco," "queso fresco," or Panela - unless they're made with pasteurized milk. Make sure the label says, "made with pasteurized milk."
Refrigerated pâtés or meat spreads.
Refrigerated smoked seafood - unless it's in a cooked dish, such as a casserole. (Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna, or mackerel is most often labeled as "nova-style," "lox," "kippered," "smoked," or "jerky. " These types of fish are found in the refrigerator section or sold at deli counters of grocery stores and delicatessens.)
Raw (unpasteurized) milk or foods that contain unpasteurized milk.
It's okay to eat:
Canned or shelf-stable (able to be stored unrefrigerated on the shelf) pâtés and meat spreads.
Canned or shelf-stable smoked seafood.
Pasteurized milk or foods that contain pasteurized milk.
Note: See your doctor or healthcare provider if you have questions about listeriosis.
4 main symptoms of listeriosis and how to avoid it
Listeriosis is a foodborne bacterial disease that can lead to devastating consequences in pregnant women and people with weakened immune systems. Listeria is most commonly found in improperly processed and cooked meats and unpasteurized dairy products.
Healthy people rarely experience this infection, but it can be fatal for newborns or unborn babies. Immunocompromised individuals are also at higher risk of life-threatening complications. That is why, at the first suspicion, it is necessary to take an analysis for listeriosis. Timely treatment helps prevent or mitigate the development of complications. nine0003
The peculiarity of this bacterium is the ability to survive and develop in chilled and even frozen foods. For this reason, people who are at higher risk of infection should avoid foods that may contain this bacterium.
If you develop this infection, you may experience the following symptoms:
Symptoms of listeriosis may appear several days after eating contaminated food. However, for some, a month or even more passes before the first signs of the disease appear. nine0003
If listeria spreads to the nervous system, the patient may experience additional symptoms, including:
Hardening of the neck muscles,
Confusion in the mind,
Loss of balance,
How does listeriosis manifest itself during pregnancy and newborns?
Compared to other healthy adults, pregnant women are more susceptible to this infection. In most pregnant women, the bacterium causes only mild symptoms. But the consequences for the child can be dire. The baby may die unexpectedly or face a life-threatening infection during the first days after birth. Sometimes miscarriages happen. nine0003
As with adults, listeriosis symptoms in newborns may be mild. They include:
Weak desire to eat,
Listeriosis in people with weakened immunity:
This category of people includes:
persons over 60 years old,
people who are taking place chemotherapy,
People with kidney disease or diabetes,
People taking large doses of prednisone or certain drugs for rheumatoid arthritis,
People taking drugs after organ transplants (immunosuppressants).
Listeria can be found in soil, water or animal feces. Most often people become infected after eating:
Unpasteurized milk or products made from it0012
Raw vegetables that have been contaminated from soil or manure used as fertilizer.
When to run to the doctor?
If you've been eating foods that have since been taken off the market because of Listeria, listen to your body. If the four main symptoms appear, immediately go to the doctor. The same goes for eating foods that may have been contaminated: unpasteurized milk, an undercooked hot dog, or deli meats. If after using them symptoms of listeriosis appear, go get tested. nine0003
If you have additional symptoms that affect the nervous system, call an ambulance. These symptoms may indicate the development of one of the life-threatening complications - bacterial meningitis.
In most cases, this infection is so mild that patients may not notice anything. But this does not negate the fact that this disease can lead to life-threatening complications. These include:
Blood poisoning (septicemia),
Inflammation of the membranes and fluid that surrounds the brain (meningitis),
Miscarriage in early pregnancy (in 20% of cases),
The development of a deadly infection in a child during the first days after birth (even if the infection was very mild in the mother).
The most effective way to detect this infection is through a blood test to determine the DNA of the bacterium. By the way, if you live in Kyiv, you can take this test at our medical center in Troyeschina. nine0003
In some cases, additional research methods are required - analysis of urine or cerebrospinal fluid.
Treatment for listeriosis varies according to the severity of the symptoms. Most people with a mild infection do not need to be treated, but should be monitored by a doctor. In severe cases, antibiotics are prescribed.
Listeriosis during pregnancy must be treated very quickly. The main goal is to prevent the transmission of infection from mother to child. If the baby was born with this infection, he may be prescribed a combination of several antibiotics. nine0003
as prevent This ?
To prevent listeriosis infection, follow these simple guidelines:
Practice good hygiene: always wash your hands thoroughly with soap and water before and after preparing food. After cooking, wash utensils and surfaces, especially cutting boards. In this case, it is necessary to use detergent and hot water. nine0012
Thoroughly clean the surface of raw vegetables with a peeling brush or a vegetable brush. Do this under strong running water.
Bring food to full readiness. Check each time that meat and egg dishes have been fully cooked through.
Precautions for people at risk
Recall that this group includes pregnant women and immunocompromised people. In their case, it is necessary to apply additional preventive measures with the following types of products:
Unpasteurized milk - cut it out completely.
Soft cheeses. Avoid soft cheeses like feta, brie, camembert and blue cheese unless the label says the cheese was made with pasteurized milk.
Hot dogs and deli meats. Eat them only if they have been thoroughly cooked under high temperature (until steam appears). Wash your hands thoroughly after preparing hot dogs and charcuterie.
Chilled or frozen smoked seafood and dried meats. Do not eat these foods. Only canned smoked seafood is acceptable. nine0012
Now you know how to reduce your risk of contracting Listeria. According to the Centers for Disease Control and Prevention, 260 people die from this infection every year in the United States. Therefore, at the first suspicions, it is better to take an analysis for listeriosis and be calm.
Listeria infection, Mayo Clinic,
What Is Listeria, WebMD,
Listeria (Listeriosis), Centers for Disease Control and Prevention, CDC. nine0195
Listeriosis - Symptoms, Diagnostics and Treatment
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Last updated: 21 July 2021
Listeriosis is a Gram-positive bacterial infection that primarily affects newborns, pregnant women, adults 45 to 50 years of age, and immunocompromised people. nine0003
This disease is mainly transmitted through food. Prevention consists of practicing good hand hygiene, preparing food thoroughly, and avoiding unwashed and leftover food.
Outbreaks have been reported worldwide with melons, frozen vegetables and chilled pork as the source of infection.