Maternal infections can be asymptomatic.
Reservoir Environment, cattle, sheep, soil, silage. The bacterium has been isolated from a range of raw foods including vegetables and uncooked meats as well as processed foods. A wide range of food products have been implicated in outbreaks including soft cheeses and meat based pat s. Commonly carried in the human gut. The majority of cases are believed to be foodborne. Some cases by direct contact with animals.