Facts About Listeria

What Is Listeria?

Listeria is one of the few foodborne threats that behaves in a way most people do not expect. While refrigeration is widely relied on to slow or stop bacterial growth, Listeria Monocytogenes can survive and continue to grow at refrigerator temperatures. That ability alone makes it fundamentally different from many other pathogens and is a key reason it remains a persistent concern in modern food systems.

Listeria is commonly found in the environment, including soil and water, making it a bigger challenge for manufacturers to ensure it does not make its way into the food. What makes it particularly problematic is not just its presence, but the conditions that allow it to thrive. Unlike many bacteria that are kept in check by cold storage or by competition from other microbes, Listeria persists in cold environments and takes advantage of situations where processing has reduced the competing bacteria.

Risk to People:
While there are 28 strains of Listeria, only one poses a health risk, the L. Monocytogenes strain. In the United States, infections are relatively rare, with approximately 1,250 cases reported annually. However, the severity is disproportionately high, with about 175 deaths each year and a fatality rate near 14 percent. Unlike more common foodborne illnesses such as Salmonella, which are often self-limiting, Listeria infections are more likely to require hospitalization and can become life-threatening, particularly for older adults and individuals with weakened immune systems.

Since Listeria can be found in soil and water, and thrive in the refrigerator, the best precaution you can take is to keep your refrigerator clean and sanitized, and wash hands frequently.

Can I Get Listeria From My Pets?
Infections are rare in dogs and cats and there are no reports of pets giving listeria to humans or vice versa.

Summary:
The best way to protect yourself against Listeria is to recognize that refrigeration and freezing do not kill the bacteria. Instead, be diligent in washing hands after handling food. Since Listeria can thrive in cold temperatures, frequent cleaning and sanitizing of your refrigerator helps to keep you and your family safe.