A foodborne pathogen or bacteria, referred to as Listeria monocytogene that causes illness from items that have been improperly handled, processed, or cooked, such as meats, poultry, seafood, and produce. Similarly, dairy products that are unpasteurized or not processed properly may also develop the bacteria and cause the illness, such as soft cheese and unpasteurized milk. Since the Listeria bacteria can grow in soil and water which may become infected from animal wastes, uncooked foods made with items such as fresh vegetables, raw meat or unpasteurized milk may retain the bacteria. Typically, the process of pasteurization and cooking will eliminate the bacteria, but not in all instances. Listeria has been shown to exist in processed foods such as meats that have been cooked, then infected and then packaged, thus carrying the bacteria into the packaged product.
Serious complications and disease may result for pregnant women, newborn children, or adults who have weakened immune systems. For pregnant women, complications may include stillbirth, the delivery of a child prematurely, or spontaneous abortion. Initial symptoms from Listeria include nausea and diarrhea. As the bacteria spreads and infects the nervous system, an individual may develop headaches, problems with balance or equilibrium, a stiff neck, and possible convulsions.