Eggs are a simple, cost effective and nutritious part of our diet. You should be aware though that eggs can be contaminated by the food poisoning bacterium Salmonella when they are laid. While the egg industry supplies fresh eggs as safe as possible they can be a source of food poisoning if not handled or cooked properly.
This is particularly true for uncooked dishes, sauces and dressings containing raw or lightly cooked eggs. Examples of dishes that have commonly caused outbreaks of food poisoning include uncooked desserts such as mousses and tiramisu; sauces and dressings such as hollandaise; fresh mayonnaise, and aioli; drinks containing raw egg such as egg nog and health shakes with added raw egg, and steak tartare. These foods are risky if eaten uncooked and need to be handled safely.
Some other foods containing raw egg you might not think about and that have caused food poisoning during preparation or after inadequate cooking include: pies glazed with raw eggs, raw dough (pasta, muffins) or batter (pancakes) eaten before baking/cooking, the coating used for deep fried ice cream, dumplings undercooked by adding for only a very short time to already cooked stew, soup or broth.
Consumption of foods containing raw or minimally cooked eggs alone or in combination with other ingredients is currently the single largest cause identified in foodborne outbreaks caused by Salmonella. OzFoodNet reported that in 2011 in Australia, more than one third of all foodborne outbreaks identified were linked to eggs and egg-based dishes (29 outbreaks, affecting 498 people in total). These outbreaks represented just under half of all the outbreaks caused by Salmonella.
The foods linked with these outbreaks included many of those listed above. In 2011, two thirds of the outbreaks were linked to food prepared in takeaways, restaurants, bakeries and care facilities, with the remaining one third prepared in private residences. In these outbreaks, OzFoodNet reported that eating raw eggs or food or ingredients containing raw eggs, undercooking and cross-contamination of food, and poor cleaning of food preparation equipment were practices leading to the food eaten being unsafe.
According to a national Newspoll survey conducted for the Food Safety Information Council, nearly 20% of Australians are taking risks by not handling uncooked foods containing raw egg correctly. Almost 1 in 5 surveyed did not know that homemade mayonnaise containing egg should be refrigerated straight away: with 9% incorrectly saying refrigerate it after a few hours, 2% incorrectly saying it could be left out of the refrigerator overnight and 7% not knowing what to do at all.
Follow these tips to minimise your risk of food poisoning from eating eggs:
- Stop and think about where an egg comes from It’s always important to follow good hygiene when handling eggs so as to not transfer contamination from the egg shell surface to other foods you are handling that are not going to be cooked.
- Dishes containing raw eggs as an ingredient, that aren’t going to be cooked before being eaten, should not be served to vulnerable people at greater risk from food poisoning such as small children, pregnant women, the elderly and people with compromised immune systems.
- Egg meals should be cooked for these vulnerable people until the yolk in a boiled egg has started to become firm or eggs have become set in omelets or scrambled eggs.
- Do not buy cracked or dirty (e.g. visible faeces, feathers) eggs. These are more likely to be contaminated with Salmonella. Bring the presence of any eggs like this to the attention of the seller as it against food safety legislation to sell cracked and dirty eggs. If eggs get a crack in them while you handle or transport them, it’s safest to discard them or cook them thoroughly as soon as possible, for example in a baked cake.
- If you accidentally drop pieces of shell into your egg mixture while preparing food, it could contaminate the mixture and it will need thorough cooking. Remove the shell pieces with a clean spoon or fork.
- Wash your hands with soap and running water and dry thoroughly before handling any food including raw eggs and after handling eggs so you don’t contaminate other food.
- If you are not going to cook the eggs further, don’t separate the yolk from the white using the shell as that could contaminate either part of the raw egg. Invest in an egg separator.
- Prepare raw egg foods just before you are going to consume them and if you need to store the dish refrigerate it immediately at 5°C or below, so the bacteria cannot grow.
- It is recommended to keep your eggs refrigerated in the cardboard box you purchased them in. This will not only keep them fresh longer, but you’ll also be able to check the ‘best before’ date on the box.
Have chooks at home?
If you have your own hens, keep the nesting materials and litter clean and dry and change it regularly, gather eggs from their nesting places daily. Carefully check any eggs for cracks, wipe off any visible dirt with a dry cloth or paper towel but don’t wash the eggs in water – this can transfer the contamination into the egg contents. Always remember to wash your hands with soap and water and dry thoroughly after handling eggs. If your children and grandchildren have been helping to collect the eggs, be sure they wash their hands too.