Medicines for Listeria infection

What it is

Listeriosis is an infection caused by Listeria bacteria, usually caught from contaminated food. Unlike most food-poisoning bacteria, Listeria can grow even at refrigerator temperatures, and is found in certain higher-risk foods — such as unpasteurised milk and dairy products, soft cheeses (like brie, camembert and blue-veined cheeses), pâté, cooked sliced meats and cured meats, smoked fish, and pre-prepared or chilled ready-to-eat foods that are not reheated. In most healthy people, listeriosis causes no symptoms or only a mild, short-lived illness with flu-like symptoms or mild gastroenteritis, and they recover without problems. However, its importance lies in the fact that it can cause serious illness in specific higher-risk groups: pregnant women (in whom even a mild maternal illness can cause miscarriage, stillbirth, or serious infection in the newborn), newborn babies, older people, and people with weakened immune systems, in whom it can lead to severe infections such as blood infection (sepsis) and meningitis. This is why, although uncommon, listeriosis is taken seriously and why advice on avoiding higher-risk foods is targeted particularly at pregnant women and other at-risk groups.

How it is treated

For a healthy person with a mild illness, listeriosis usually settles on its own with supportive care, and often no specific treatment is needed. However, in the higher-risk groups, and in anyone with more serious illness, prompt treatment with antibiotics is important, sometimes in hospital, along with support for any complications. In pregnancy, any suspected listeriosis needs prompt medical assessment and treatment because of the risk to the baby, and the baby may be monitored or treated. Diagnosis is by blood tests or other samples. Because prevention is so important for at-risk groups, dietary advice is key: pregnant women, older people, and those with weakened immunity are advised to avoid the higher-risk foods (such as unpasteurised dairy, certain soft and blue cheeses unless cooked, pâté, and chilled ready-to-eat foods unless thoroughly reheated), and everyone benefits from good food hygiene — storing food correctly, observing use-by dates, keeping the fridge cold, avoiding cross-contamination, and reheating food thoroughly. The reassuring message is that listeriosis is uncommon and usually mild in healthy people, but because it can be serious in pregnancy and other at-risk groups, prevention through food choices and hygiene, and prompt treatment when needed, are important.