Listeriosis is a rare bacterial infection caused by a family of bacteria called Listeria. Listeria family contains ten different species, being Listeria monocytogenes the main responsible of causing listeriosis.
Listeria monocytogenes is a facultative anaerobic Gram-positive bacterium, capable of surviving in the presence or absence of oxygen. Listeria monocytogenes is one of the most virulent food-borne pathogens, responsible for an estimated of 260 deaths per year only in the United States.
How can you get listeriosis?
Listeriosis is usually caught from eating food containing listeria bacteria which can be found in soil, plants and water. Animals, including cattle, sheep and goats, can also carry the bacteria. Infections can also occur through contact with infected animals or people.
Listeria has been isolated from raw meat, dairy products, vegetables, fruit and seafood. Soft cheeses, unpasteurized milk and unpasteurised pâté are potential dangers.
How can you prevent listeriosis?
The main means of prevention consist of hand hygiene, cooking food well, and avoiding unwashed and leftover food.
As described above, you can get it from lots of types of food, but it’s mainly a problem with:
- Unpasteurised milk
- Dairy products made from unpasteurised milk
- Soft cheeses, like camembert and brie
- All types of pâté
- Any undercooked food
Cooking at temperatures higher than 65 °C kills the bacteria. However, Listeria can contaminate foods after production.
what are the signs and symptoms of listeriosis?
In most infected people, listeriosis has no symptoms or only causes mild symptoms for a few days, such as:
- Mild flu-like symptoms
- High temperature of 38 °C or above
- Aches and pains
- Feeling sick or vomiting
However, in more severe cases, listeria infection can lead to more serious infections such as meningitis and other potentially life-threatening complications. Treatment includes prolonged administration of antibiotics, primarily ampicillin and gentamicin.
Is listeria infection dangerous?
Listeria infection usually goes away on its own and, although its incidence is relatively low in the general population, it can cause serious problems if you are pregnant or have a weak immune system.
Briefly, as with most opportunistic pathogens, those with weakened immune systems, underlying health issues, the very old or young, newborns and pregnant women are most at risk.
In people with weak immune systems it can lead to meningitis or septicaemia. In addition, pregnant women are 10 times more likely to contract listeriosis and can result in a miscarriage or stillbirth, premature delivery, or meningitis in the newborn.
The Centers for Disease Control and Prevention (CDC) estimates that listeria is the third leading cause of death from food-borne illness, or food poisoning, in the United States. Most people with invasive listeriosis require hospital care, and about one in five people with the infection die. Listeriosis during pregnancy results in fetal loss in about 20% and newborn death in about 3% of cases.