What is Listeriosis? Listeriosis is an illness that arises from serious infection usually caused by when a person eat contaminated food with bacterium listeria. Infection is uncommon but most frequently affect pregnant women, newborn, adult and old people whose immunity is weak. In pregnant women this infection causes miscarriage. It cause wide range of infection include pneumonia, osteomyelitis and meningitis. Causes of Listeriosis : Listeria bacteria can be found in water, soil, plants, decaying vegetation and animal feces. Contamination can occur at any point in the distribution, farming and food distribution. Some factors are: Raw vegetables that can contaminated from the soil or from manure used as fertilizer. Raw milk product made from raw milk Certain process food- hot dogs, deli meats, soft cheese that have contaminated Most often this bacteria cause gastrointestinal illness, skin lesion and abscesses. In some causes you can develop inflammation or blood infection.