Listeria in Food: What You Need to Know

What Is Listeria Monocytogenes?

Listeria monocytogenes is a species of bacteria found in soil, water, and some animals. Unlike most foodborne bacteria, Listeria can grow at refrigerator temperatures (35-40 F), which makes it particularly dangerous in ready-to-eat foods that are not cooked before consumption.

According to the CDC, Listeria causes an estimated 1,600 infections and approximately 260 deaths in the United States each year. While the total number of infections is lower than Salmonella or E. coli, the hospitalization rate (approximately 94%) and fatality rate make it one of the leading causes of death from foodborne illness.

Who Is at Risk?

Most healthy adults who are exposed to Listeria experience only mild symptoms or none at all. However, certain groups are significantly more vulnerable:

• Pregnant women: About 10 times more likely to get listeriosis than the general population. Infection during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.
• Adults 65 and older: The risk of invasive listeriosis increases significantly with age due to natural changes in the immune system.
• People with weakened immune systems: This includes individuals undergoing cancer treatment, organ transplant recipients taking immunosuppressive drugs, and people with HIV/AIDS, diabetes, liver disease, or kidney disease.
• Newborns: Infants can acquire Listeria from their mothers during pregnancy or delivery.

Symptoms and Timeline

Listeriosis symptoms vary depending on whether the infection is invasive (spreading beyond the gut) or non-invasive:

Non-Invasive Listeriosis

Symptoms typically appear within 24 hours and include diarrhea, fever, headache, and muscle aches. This form usually resolves on its own within a few days and does not require antibiotics in most healthy adults.

Invasive Listeriosis

The more dangerous form occurs when the bacteria spread beyond the intestines into the bloodstream or brain. Symptoms can take 1 to 4 weeks to appear (and in some cases up to 70 days). They include:

• High fever
• Severe headache
• Stiff neck
• Confusion or loss of balance
• Convulsions

Invasive listeriosis requires immediate medical treatment with antibiotics. If you are in a high-risk group and have consumed a product recalled for Listeria, contact your doctor even if you do not have symptoms yet.

High-Risk Foods

Listeria contamination is most commonly found in foods that are eaten without further cooking. The highest-risk food categories include:

• Soft cheeses: Brie, Camembert, queso fresco, feta, and blue-veined cheeses made with unpasteurized milk are particularly susceptible.
• Deli meats and hot dogs: Ready-to-eat meats can become contaminated during processing, even after cooking. The FDA recommends heating deli meats to 165 F before eating if you are in a high-risk group.
• Smoked seafood: Refrigerated smoked fish (such as lox or smoked salmon) is a known Listeria risk. Canned or shelf-stable smoked seafood is safe.
• Raw sprouts: Alfalfa, clover, and other sprouts are grown in warm, humid conditions that favor bacterial growth.
• Unpasteurized dairy: Raw milk, raw milk yogurt, and ice cream made with raw milk can carry Listeria.
• Pre-cut fruits and vegetables: Pre-packaged salads, sliced melons, and other cut produce can harbor Listeria, especially if held at improper temperatures.

Listeria Recalls by the Numbers

Our database shows 1,298 FDA food recalls related to Listeria contamination. Of these, 1,071 are classified as Class I (dangerous), reflecting the serious health risk this pathogen poses.

There are currently 44 active Listeria-related recalls. Check the full Listeria recall list for details.

Brands with the most Listeria-related recalls:

How to Prevent Listeriosis

Because Listeria can grow at refrigerator temperatures, standard food safety practices need to be supplemented with additional precautions:

• Keep your refrigerator at 40 F or below and your freezer at 0 F or below. Use a thermometer to verify — do not rely on the dial setting alone.
• Clean your refrigerator regularly. Listeria can survive and spread on refrigerator surfaces. Wipe up spills immediately, especially juices from deli meats, hot dogs, and raw meat.
• Use ready-to-eat foods promptly. Once opened, consume deli meats, hot dogs, and smoked seafood within 3-5 days.
• Heat deli meats and hot dogs to 165 F if you are in a high-risk group. This kills any Listeria that may be present.
• Avoid cross-contamination. Keep raw meat separate from ready-to-eat foods. Wash hands, knives, and cutting boards after handling raw foods.
• Choose pasteurized products. Select cheeses, milk, and juices made from pasteurized milk, especially if you are pregnant or immunocompromised.

For the full list of Listeria-related recalls, visit our Listeria recall tracking page.