See: [Milk borne diseases](https://en.wikipedia.org/wiki/Milk_borne_diseases) - [cubox](cubox://highlight?id=7345801532371110314), [Raw milk - bear](bear://x-callback-url/open-note?id=F27D4DCE-34FA-4E51-B1CC-8B72973DD803-9486-000005353D9691DD) Listeriosis primarily affects: - Immunocompromised individuals (e.g. those with leukemia, diabetes, or cancer) - Elderly patients - Pregnant women and their fetuses - Newborn infants - Individuals on immunosuppressive therapies (e.g. corticosteroids) In healthy, nonpregnant adults, listeria infection is rare and typically limited to mild, self-limiting, flu-like symptoms or febrile gastroenteritis following ingestion of contaminated food. In immunosuppressed, nonpregnant adults, listeriosis may present more severely as: - Acute meningoencephalitis - Brain abscess - Bacteraemia Other possible manifestations include: - Pneumonia - Endocarditis - Infected prosthetic joints - Localised internal abscesses eg liver, other organs  Presentation may be acute or subacute, with approximately 60% of cases developing symptoms more than 24 hours after exposure. Notably, the **incubation** period for listeriosis can be **up to 70 days**, so continued vigilance is required for several weeks following exposure. Common symptoms include: - Fever - Severe headache - Nausea and vomiting These may progress to prostration and shock in severe cases.