Foodborne illnesses

Some women might say that one of greatest challenges faced in pregnancy are the restrictions placed on certain food products for fear of foodborne infections.

Despite public awareness efforts, pregnant women today are misinformed or lacking in knowledge about foodborne illnesses. This is highlighted in a recent publication, which found that 60% of pregnant women were unaware of the foods linked to Listeriosis risk, and 25% or 1 in 4 women were consuming unsafe or highly risky foods.

What are foodborne illnesses?

The three common infections are salmonella, listeriosis, and toxoplasmosis. Of these salmonella is the most frequently reported with about 6000 cases reported in Australia each year. Listeria on the other hand is rare with only 60 cases reported each year, however 10 of these are in pregnant women.

1. Salmonella

  • Salmonella is a bacteria that colonizes the intestinal tract of both humans and animals and is excreted in faeces, thus contaminating food sources which come into contact with these.
  • More commonly the organism is associated with poultry products, such as egg and chicken, however also contaminates beef, pork, milk and vegetables.
  • Salmonella causes gastrointestinal symptoms such as vomiting, diarrhea and fevers, leading to significant dehydration, and although rare if severe illness can lead to miscarriage.

2. Listeriosis

  • Listeriosis is a rare but very serious foodborne illness caused by the organism Listeria monocytogenes. It is widespread in nature, found in both vegetation, untreated water and food processing facilities, and has the capability to multiple in refrigerator temperature as well as survive incomplete cooking.
  • If you become infected with Listeriosis you may have very mild and vague viral symptoms or no symptoms at all, however the infection can be transferred across the placenta to your baby causing severe neonatal infections that can be potentially fatal.
  • Listeriosis can lead to miscarriage, stillbirth, or neonatal infection. Your baby may be very ill when born, suffering from septicaemia or meningitis. Neonatal problems caused by listeriosis only occur in 1 out of every 5 women who contract the infection.

3. Toxoplasmosis

  • Toxoplasmosis is caused by the parasitic organism Toxoplasma gondii.
  • It is a rare infection, with organism living in an environment hosted by cats, and transmitted throughout the environment in their faeces. An interesting yet frightening statistic is that 48% of cats are infected with this parasite.
  • Infection occurs when humans consume food or water that has been in contact with cat faeces. This has detrimental effects on the fetus causing blindness, learning disabilities and mental retardation.

What foods should I avoid?

Avoiding high risk foods will ensure that you have reduced the risk of contracting any of the foodborne infections. These include:

  • Raw / uncooked / smoked meat and seafood
  • Deli meats, cooked cold meat, pate, meat spreads
  • Leftovers, more than 24hours after cooking
  • Pre-prepared salads, smorgasboards and buffets
  • Unpasteurised milk and soft serve icecream
  • Soft cheeses
  • Unwashed raw fruit and vegetables
  • Raw eggs or foods containing raw or partially cooked eggs


What other changes can I make to my diet and food preparation?

  • Aim for a diet full of freshly prepared and cooked meals. This minimizes the amount of exposure to bacteria your foods will face. Bacteria tend to grow over time so avoid eating food if it has been prepared more than 24hours earlier.
  • Wash all raw vegetables and fruits prior to consumption.
  • Keep uncooked meats separate from other cooking items, by using separate cutting boards and utensils. Store uncooked meats separate from vegetables and ensure that there is no chances it can drip onto other fooods.
  • Wash hands before preparing foods, as well as after chopping and touching uncooked meats.
  • Heat leftovers to steaming hot temperatures prior to consumption. The rough rule is that the food should have been exposed to high heating above 74 degrees for at least 2 minutes.
  • Look for clear juices before consuming freshly cooked chicken or pork. This is a sign that it has been thoroughly cooked.
  • Do not consume any leftovers greater than 12hr old.
  • Avoid partially cooked eggs, such as dips, salad dressing, mayonnaise, desserts
  • Do not consume food that is meant to be stored in the fridge if it has been left out for at least 2 hours. Cover and cool any food in the fridge, not on the bench top.
  • Defrost ready-to-eat frozen foods in the fridge. Do not thaw on the bench or at room temperature.

Additional information on Foodborne illnesses can be found on the Links page. Please don’t hesitate to ask or email any further questions that you may have.


2 responses to “Foodborne illnesses

  1. Phoebe

    Hi there – I am slightly confused about the literature and reading in relation to Listeriosis. My obstetrician told me that if you were to contract this, you would generally feel extremely unwell with very high fevers and abdominal pain, however on a lot of reading online, it says the symptoms can be vague. Do you have any clarification? Thanks so much!

  2. Julia

    So is it best to avoid leftovers for lunch if they were cooked the evening before for dinner? (One part of the post says to avoid leftovers more than 24 hours after cooking, but the summary at the end says to avoid leftovers more than 12 hours old so I wasn’t sure.) Thank you :)

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