Listeria infections

Listeria infections, also called listeriosis, are bacterial infections caused by Listeria monocytogenes, usually acquired by eating contaminated food. The infection is rare, though severe invasive disease makes it a concern for public health. Chilled ready-to-eat foods such as cooked sliced meats, smoked fish, soft mould-ripened cheeses, pâté and unpasteurised dairy carry the greatest risk, since the bacteria multiply at refrigerator temperatures; spread from people or farm animals is less common. Many people have no symptoms or only fever, aches, chills, vomiting and diarrhoea, whereas pregnancy, the newborn period, older age and weakened immunity raise the risk of sepsis, meningitis, miscarriage or stillbirth. Diagnosis rests on symptoms and detection of the bacteria in blood, cerebrospinal fluid or other samples, including polymerase chain reaction testing. Listeriosis is treatable with antibiotics, used for severe disease and higher-risk patients, and prompt treatment in pregnancy helps protect the fetus or newborn.

Seek urgent care for a high fever with a stiff neck, rash, confusion, difficulty breathing, or fever after travel to a malaria area. See a doctor when a fever lasts more than three days, when symptoms return after treatment, or when you may have been exposed to an infection that needs testing. Call the local emergency number for any symptom that is sudden and severe. This page is a reference for healthcare professionals and does not replace an assessment.