Listeria monocytogenes is a harmful bacterium that causes foodborne illnesses, primarily through contaminated food. The bacterium thrives in various environments, including soil, water, and animal feces, and can contaminate food during growth, harvest, processing, or storage.
Listeria enters food supplies through several pathways. Animals may carry the bacterium without showing symptoms, contaminating meat and dairy products during slaughter or milking. Vegetables can become contaminated through contact with infected soil or water. Processing facilities can harbor Listeria in drains, equipment, or surfaces, leading to cross-contamination.
The bacterium's ability to grow at refrigeration temperatures makes it particularly dangerous. Unlike many other foodborne pathogens, Listeria can multiply in foods stored at typical refrigerator temperatures (34°F to 40°F), increasing the risk of contamination over time.
Certain foods are more likely to harbor Listeria:
A study by the Centers for Disease Control and Prevention (CDC) found that deli meats and soft cheeses were responsible for 46% of Listeria outbreaks between 2000 and 2018.
Listeria primarily affects pregnant women, newborns, older adults, and individuals with weakened immune systems. Pregnant women are 20 times more likely to contract listeriosis, which can lead to severe complications like miscarriage, stillbirth, or life-threatening infections in newborns.
Older adults and immunocompromised individuals are also at high risk due to their reduced ability to fight infections. According to the CDC, people aged 65 and older account for 64% of Listeria-related hospitalizations.
To reduce the risk of Listeria infection, follow these guidelines: