Listeria is a rare but potentially life-threatening disease. Healthy adults are likely to experience only mild infection, causing flu-like symptoms or gastroenteritis. However, listeria infection can occasionally lead to severe blood poisoning (septicaemia) or meningitis.
Listeria bacterium(Image: CDC)
Pregnant women, the elderly and people with weakened immune systems are more susceptible to listeria. It is particularly dangerous in pregnancy as although the illness is unlikely to be serious for the mother, it can cause miscarriage, premature delivery or severe illness in a newborn child.
Listeria is an unusual bacterium because it can grow at low temperatures, including refrigeration temperatures of below 5°C. It is, however, killed by cooking food thoroughly and by pasteurisation. Foods most likely to be contaminated with listeria are soft cheeses, cold cuts of meat, pâtés and smoked fish, or ready meals which have been pre-cooked and then chilled for some time before consumption.
Public Health England (PHE) is involved with detecting cases of listeria infection, as well as monitoring any outbreaks. We provide advice on controlling outbreaks and, where possible, track the source, e.g. the food that has caused the illness, so that we can stop other people from becoming infected. PHE is also involved with testing foods for the presence of L. monocytogenes.