Listeriosis, the illness caused by Listeria monocytogenes, is relatively uncommon, affecting about 1,600 people a year (compared with 1.35 million sickened by salmonella, for example). Symptoms can include fever, muscle aches, nausea, vomiting, and diarrhea.
For healthy adults who have mild symptoms, the illness will resolve on its own, the FDA says.
But very young children, older adults, and individuals who are pregnant or have a condition that compromises the immune system are at greater risk of becoming seriously ill. For example, a pregnant person is 10 times more likely to become sickened with listeriosis when exposed to listeria, according to the Centers for Disease Control and Prevention.
Contact your healthcare provider if you experience headaches, stiff neck, confusion, loss of balance, or convulsions; these symptoms can be a sign of a more invasive listeriosis infection.