Interest in foodborne listeriosis escalated rapidly during the 1980s and continues as a result of several major outbreaks of the illness and the occasional recovery of the causative agent, Listeria monocytogenes, from raw and ready-to-eat processed foods. Listeria monocytogenes, the causative agent of listeriosis, is a Gram-positive, non-spore-forming, non-acid-fast, pleomorphic, rod-shaped bacterium with rounded ends. It is widely distributed in the environment. The bacterium has been isolated from soil; vegetation; fecal material from many animals, birds, and humans; sewage, and water. Listeriosis of goats is essentially the same as that of sheep. Meningoencephalitis is the form that predominates in goats, although reports of listeric abortion are common. Listeriosis is of minimal concern to healthy persons, but certain segments of the population, including pregnant women, newborns, and adults suffering from an underlying condition that results in a compromised immune system, can develop life-threatening illness.