Food Safety During Pregnancy - Part 1: Listeria and more.
Co-Written by Emily Stevens, Dietetics Student
We often hear about listeria being a big concern when it comes to food safety during pregnancy - but if you’ve ever wondered why it matters or what exactly it is, read on! We will also touch on some other bacteria, and one parasite, that are important to be aware of during pregnancy (Salmonella, Campylobacter, Toxoplasma).
Part 2 of our Pregnancy Food Safety series will come this Thursday, April 15th, so keep an eye out!
Listeriosis is a foodborne illness that occurs when foods that contain the bacteria Listeria monocytogenes are ingested (2). This is one of the most prevalent food borne illnesses that occur with pregnant women, as it primarily affects those with compromised immune systems, such as during pregnancy (2).
This bacterium can survive in various conditions, including in refrigerator temperatures, in foods with preservatives, and in packaging that allows little to no oxygen (2). Listeria is however able to be killed by cooking (2), because of this, it is important that proper food handling is followed with foods that lend an increased risk of carrying this bacterium. The risks associated with contracting listeriosis during pregnancy may include flu-like symptoms for the mother, with more serious complications including miscarriage, stillbirth, and infection to the baby if untreated (2).
Foods associated with a risk of Listeriosis (2,3):
Soft cheeses
Unpasteurized milk products
Unpasteurized fruit juice and cider
Pate
Processed meats, such as hot dogs, luncheon meats, and deli meats
Raw or undercooked meat, poultry, seafood, and eggs
Raw sprouts and pre-packaged fruit and vegetable salads
Safer choices (3):
Hard cheese (parmesan, cheddar, swiss, and Colby)
Processed cheese slices and spreads (including cream cheese and cottage cheese)
Pasteurized milk and milk products (check the label to make sure it says pasteurized!)
Pasteurized fruit juice
Refrigerated pates, meat spread and smoked seafood that have been cooked to an internal temperature at 165 °F (heat until steaming hot and eat soon after)
Pasteurized soft and semi-soft cheese (brie, camembert, feta) that has been cooked to an internal temperature of 165 °F (heat until steaming hot and eat soon after)
Other bacteria that are of increased concern during pregnancy include Salmonella, Campylobacter, and Toxoplasma:
Salmonella:
Salmonellosis occurs when food that contains Salmonella bacteria is consumed (2). Salmonella does not survive at refrigerator and freezer temperatures and can also be eliminated through proper cooking and heating (2). Salmonellosis causes flu-like symptoms and gastrointestinal symptoms such as nausea and vomiting (2). In some cases (although rarer), miscarriage and premature labour can be consequences of salmonellosis (1). To avoid infection, proper hygiene and food safety handling should be taken when working with at risk foods (2).
Foods associated with a risk of Salmonellosis (1,2):
Raw or partially cooked eggs
Mayonnaise (with raw or unpasteurized eggs)
Soft-serve ice cream
Uncooked meat (especially poultry and seafood)
Raw Sprouts
Unpasteurized fruit juice
Unwashed fruits and vegetables
Safer choices (2):
Fully cooked eggs, and shelf-stable mayonnaise made with pasteurized eggs
Carefully washed fruits and vegetables
Pasteurized fruit juices
Meat and poultry that is cooked to an internal temperature of 165°F
Campylobacter:
Campylobacteriosis occurs when food or water that contains Campylobacter jejuni bacteria is consumed (2). This bacterium can be eliminated through proper heating of food to a minimum of 120°F and is inhibited by acid, salt, and drying (2). Pregnant women are not necessarily at an increased risk of serious complications due to Campylobacteriosis; however, the infection may be transmitted to the placenta, causing complications with the baby (2).
Foods associated with a risk of Campylocbacteriosis (1,2):
Unpasteurized milk
Undercooked meat and poultry
Raw shellfish
Safer Choices (2):
Well cooked meat and poultry to an internal temperature of 165°F
Toxoplasma:
Not a bacteria, but actually a parasite - Toxoplasmosis is caused by the parasite Toxoplasma gondii, which can be picked up by people through contaminated foods, but also contaminated soil, water, and cat feces (2). Typically, toxoplasmosis does not create symptoms in humans, when symptoms do appear, they may include a low-grade fever, rash, muscle aches, headaches, and potentially swollen lymph nodes (2). Toxoplasmosis may contracted through consuming unwashed fruits and vegetables, or raw and undercooked meat (2).
Foods associated with a risk of Toxoplasmosis (1,2):
Unwashed fruits and vegetables
Undercooked or raw meats
Safer choices (2)
Well cooked meat to an internal temperature of at least 165°F
Thoroughly washed fruits and vegetables
References:
1.de Seymour JV, Beck KL, Conlon CA. Nutrition in Pregnancy. Obstetrics, Gynaecology, and Reproductive Med. 2019;29(8): 219-224.
2. Dean J, Kendall P. Food Safety During Pregnancy [Internet] Food and Nutrition Series: Colorado State University; 2006; [cited 2021 Mar 27] Available from: https://mountainscholar.org/bitstream/handle/10217/195894/AEXT_ucsu2062293722006.pdf?sequence=1
3. HealthLink BC. Healthy Eating Guidelines for Food Safety during Pregnancy [Internet] PEN: The Global Resource for Nutrition Practice: HealthLink BC; 2015; [cited 2021 Mar 27] Available from: https://www.healthlinkbc.ca/hlbc/files/healthyeating/pdf/food-safety-during-pregnancy.pdf
