listeria pregnancy anxiety (2023)

What is listeriosis?

Listeriosis is a disease caused when you come into contact with a bacteria called listeria. You usually get it from eating listeria-contaminated food, but you can also get it from handling soil, water, or feces from infected animals.(FSA 2016, OTIS 2016).

When you are pregnant, you are more likely to get listeriosis. This is because changes in your immune system mean your defenses against infection are lower than normal.(NHS 2015a). Listeriosis is nearly 20 times more likely to affect pregnant women than other healthy adults(Okike et al. 2013, NHS 2015a).

Listeriosis is still a rare condition, however. There are less than 200 cases in the UK each year(PHE 2014, 2016, Scottish Government na), and up to 30 of them are pregnant women(PHE 2014). Although rare, recognizing and treating listeriosis is vital because it can seriously affect an unborn baby.

Will listeriosis harm my baby?

Listeriosis can be very dangerous for your baby(Awofisayo et al. 2015, Okike et al. 2013, NHS 2015a). The infection can be passed to your baby in the womb (womb) or during delivery(Caserta 2015).

Recognizing the infection and treating it quickly with antibiotics can help protect your baby.(Okike et al. 2013, NHS 2015a, OTIS 2016,).
However, left untreated, listeriosis can sometimes lead to:

• miscarriage
• premature birth
• a baby being stillborn(Caserta 2015, Okike et al. 2013, OTIS 2016)

If your baby is exposed to listeria in utero or during birth, he could become seriously ill after birth, with pneumonia, meningitis, or neonatal sepsis.(Caserta 2015, Okike et al. 2013). Usually, the baby's infection becomes obvious shortly after birth, but sometimes symptoms take a few weeks to appear.(Caserta 2015, Okike et al. 2013, OTIS 2016).

How will I know if I have listeriosis?

It's easy to confuse listeriosis with the flu because symptoms are usually mild.(NHS 2015a).

You can have:

• a fever
• muscle aches
• chills
• nausea or vomiting
• diarrhea(NHS 2015a)

Symptoms can appear up to 10 weeks after you've been exposed to the bacteria(NHS 2015a). To be on the safe side, see your doctor whenever you experience fever and chills during pregnancy.(NHS 2015a).

Very rarely the infection spreads to the blood or nervous system and becomes severe.(Kourtis et al. 2014, NHS 2015). In this case, the fever, muscle aches and chills will be worse, and you may develop a severe headache, stiff neck, confusion, tremors or seizures (seizures).(NHS 2015).

However, about one in three pregnant women do not experience any symptoms.(Okike et al. 2013). It is possible that the first thing you know about the infection is when you have a serious pregnancy complication or if the baby becomes sick after delivery.(Kourtis et al. 2014).

How to prevent listeriosis?

It is best to avoid foods that can cause listeriosis. Eating food contaminated with listeria is the most common cause of infection.(NHS 2015).

You are most likely to get listeria in the third trimester, when your immunity is at its lowest.(Okike et al. 2013, Kourtis et al. 2014), so it is best to take care of nutrition until the end of pregnancy.

When you're pregnant, the NHS advises you to avoid foods that are more likely to harbor the listeria bug, including:

• unpasteurized milk
• mold-ripened soft cheeses, such as camembert or brie, and blue-veined soft cheeses, such as blue danish or gorgonzola
• pâté of any kind, including vegetable pâté
• undercooked foods, such as ready-to-eat meals(NHS 2015a, NICE 2008)

It is safe to consume pasteurized or UHT milk and yogurts, including probiotic yogurts(NHS 2017). Pasteurized hard and soft cheeses such as cheddar, cottage cheese or processed cheese are also good to eat.(NHS 2017). The same goes for blue-veined hard cheeses such as stilton(NHS 2015a, 2017). Also, take extra care when handling food at home:

• Wash your hands before and after preparing meals.
• Wash kitchen utensils, cutting boards and surfaces thoroughly after preparing food.
• Keep raw and ready-to-eat foods separate in the fridge, so keep uncooked meats below ready-to-eat foods so that meat juices don't drip onto cooked foods.
• Peel or wash raw vegetables, fruits, or salads well before eating them.
• Always cook and reheat food thoroughly, according to instructions, until hot.(NHS 2015)

Unlike mold, you usually can't see when listeria has grown on your food, as it attaches to surfaces as a slime-like layer.(FSA 2016). Listeria can survive freezing and, unlike other bacteria, can continue to grow very slowly at low temperatures, such as in the refrigerator.(FSA 2016).

Most listeriosis outbreaks are associated with refrigerated and ready-to-eat foods that may have been stored too long or at the wrong temperature.(FSA 2016).

Foods that are considered safe to eat during pregnancy, but which have been most commonly associated with listeriosis, include:

• smoked fish and boiled seafood
• cooked meats, poultry and cured meats
• prepackaged sandwiches, prepared salads, and some cut fruit, including cantaloupe
  (FSA 2016)

For ready-to-eat chilled foods, it is particularly important to:

• Make sure your refrigerator is set to the manufacturer's recommended temperature, usually 5 degrees C or less.
• Eat food within the expiry date so bacteria don't have time to grow to dangerous levels.
• Follow package directions, such as how long to use food once opened.(FSA nd, NHS 2015).

It is also possible to catch listeriosis from sheep, cows and goats around the time of lambing.(DEFRA et al. 2015, NHS 2015b). If you work on a farm or visit farms with your children, stay away from sheep, cows and goats and avoid touching clothing or equipment used when handling farm animals.(DEFRA et al. 2015). This is especially important during the calving season, which is usually from January to April.(NHS 2015b).

If you or your partner are involved in agriculture, it is vital to protect yourself and your baby from listeria and other potential infections such as toxoplasmosis. You can learn more from Public Health England or the Scottish Government.

How can listeriosis be treated?

If you have any flu-like symptoms, especially if you think you ate something that could have infected you with the listeria virus, talk to your doctor right away.

If your doctor suspects listeriosis, he or she will arrange for you to have a blood test.(NHS 2015). If the results show an infection, the doctor will recommend a course of antibiotics to protect you and your baby.(Caserta 2015, Okike et al. 2013). You may also have extra ultrasound scans to check your baby's health.(NHS 2015a, OTIS 2016). It is reassuring to know that prompt antibiotic treatment is usually very successful.

Worried about something you ate? Find out what is not safe to eat during pregnancy.

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