People most at risk of serious illness from Listeria monocytogenes are the very young, the elderly and people with immune systems weakened by cancer treatments, organ transplants, AIDS, lupus and other disorders.
Pregnant women are especially at risk because the bacteria can cause miscarriages.
Listeria monocytogenes can be a threat to anyone. But healthy people usually fight off the bacteria without getting ill. If you cannot reheat these foods, do not eat them. Also wash cutting boards, dishes and other utensils. At-risk consumers can eat hard cheeses, processed cheeses, cream cheese, cottage cheese and yogurt.