Beware of listeria bacteria

Understanding Listeria – Why It Matters During Pregnancy

Being aware of Listeria bacteria is essential to avoid illness and prevent passing the infection to your baby. Listeria monocytogenes can survive high salt levels and freezing temperatures. However, it does not thrive in acidic foods and is killed by heat.

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How Does Listeria Spread?

Listeria multiplies slowly in cold environments, but the longer food is stored, the higher the risk of bacterial growth before its expiry date. The highest risk comes from eating food that has been stored in the fridge for several weeks and consumed without heating.

The bacteria can also spread in food production and handling facilities by contaminating surfaces and equipment.

Listeria and Pregnancy – What You Need to Know

Some pregnant women with listeriosis experience flu-like symptoms, while others show no symptoms at all. However, the infection can spread to the foetus, leading to severe complications, including miscarriage or serious illness in the newborn.

How to Reduce the Risk of Listeria During Pregnancy

You can lower the risk of listeriosis by avoiding certain foods and ensuring all food is heated to at least 70°C.

Tips to Reduce the Risk:

• Store refrigerated foods at a maximum of 4°C.
• Only eat freshly prepared or newly packaged smoked, cured fish products and sushi. Check the packaging date.
• Choose newly packaged cold cuts and ready-to-eat meals.
• Avoid mould-ripened and washed-rind cheeses, even if made from pasteurised milk (e.g., brie, gorgonzola, chèvre, vacherol, taleggio).
• When curing your own fish, use fresh fish stored for no more than a few days or thawed frozen fish. Consume within a week or freeze it.
• If making sushi or sashimi at home, use fresh fish stored for no more than a few days or thawed frozen fish. Eat within a few days.
• Store thawed frozen vegetables in the fridge and eat them within a few days.
• Keep cut melon refrigerated and consume within a few days.

Safe Foods You Can Eat

• Freshly made sushi or sashimi from a restaurant.
• All hard cheeses, such as Parmesan, Gruyère, Manchego, Emmental.
• Processed cheese spreads in tubes or tubs (e.g., prawn cheese, ham cheese, blue cheese spreads).
• Halloumi, mozzarella, and feta cheese (if pre-packaged or pasteurised).
• Spreadable fresh cheeses (e.g., cream cheese, ricotta, mascarpone).
• Air-dried ham and authentic salami, as they are too dry and salty for Listeria bacteria to survive.

Listeria and Processed Meats

Listeria can be found in certain deli meats, such as pâté and pre-sliced cold cuts like smoked or cooked ham and turkey. The bacteria may multiply over time, even within the product’s shelf life. However, air-dried ham and authentic salami are exceptions, as they are too dry and salty for Listeria to grow.

Listeria in Fruit and Vegetables

Listeria can multiply in frozen vegetables and melons if contaminated. If Listeria is introduced to frozen vegetables after production heating, it can grow when they are thawed. However, boiling thawed frozen vegetables kills the bacteria.

Melons, especially sweet varieties like cantaloupe, can become contaminated when cut, as the bacteria from the skin can transfer to the fruit. This is because melons do not have a sufficiently low pH to inhibit bacterial growth. To reduce the risk, store cut melon in the fridge and eat it within a few days.