Food poisoning, also called food-borne illness, is caused by eating contaminated food. Infectious organisms, such as bacteria, viruses and parasites, or their toxins, are the most common causes of food poisoning.
Any food can cause food-borne illness, but some foods are more prone to contamination than others. These are called high-risk foods. High-risk foods are typically moist, high in protein or starch and have neutral acidity, which create the ideal conditions for bacteria and other harmful microorganisms to grow.
Below is a list of five high-risk foods that commonly cause food poisoning.
Top 5 foods that can cause food poisoning
Eggs are a common source of food-borne infection in Australia, and have been linked to many high-profile outbreaks of Salmonella infection in recent years.
Salmonella bacteria is found everywhere on farms, and can easily contaminate eggs. Until recently, the bacteria could only be found on the outside of the egg, on the shell, but a new strain of Salmonella — which was previously not found in Australia — has emerged, which can contaminate the insides of eggs laid by infected hens.
Another bacteria that is frequently found in eggs is Staphylococcus aureus. Staph aureus produces toxins that are not destroyed by cooking and which cause acute symptoms of food-borne disease. The Anzac Day outbreak in April, 2019 — which saw up to 40 people “drop like flies” — was likely caused by these toxins.
To prevent food poisoning from contaminated eggs, keep eggs refrigerated at 5°C or below. Do not use cracked or damaged eggs, and cook eggs until the yolks are firm. For recipes that must contain raw egg, use only pasteurised eggs.
2. MEAT & POULTRY
Meat and poultry, especially if it's raw or undercooked, can harbour a wide range of disease-causing organisms, including bacteria, viruses and parasites (e.g. Salmonella, E. coli, Campylobacter, Listeria, Norovirus, Hepatitis A).
So pervasive is food-borne bacteria that Food Handlers must treat all raw meat as contaminated. It must be kept refrigerated and cooked to a high internal temperature to ensure food-borne bacteria and other pathogens are destroyed.
As a general rule, all meat should be cooked to a minimum internal temperature of 75°C, but safe cooking temperatures may vary depending on the type of meat.
Meat can also become contaminated — and infect other foods — via cross-contamination. To reduce the risk of cross-contamination, Food Handlers must be trained to:
- keep raw meat separate from cooked or ready-to-eat foods
- store raw meat on the bottom shelf of the refrigerator, below cooked or ready-to-eat foods like fresh produce
- clean and sanitise any equipment, surfaces or utensils that were used for meat preparation
- wash their hands after handling raw or undercooked meat and avoid working with food if they are ill
3. FRESH PRODUCE
Almost half of food poisoning cases worldwide have been linked to fresh produce. Leafy greens, fruits and sprouts can infect a person with Listeria, E. coli, Salmonella and other pathogens.
In 2018, a Listeria outbreak linked to rockmelons sickened almost 20 people and claimed four lives in Victoria and New South Wales; contaminated sprouts have been linked to dozens of food-borne illness outbreaks around the world, including one of the worst known outbreaks of E. coli.
To prevent food-borne illness from contaminated produce, Food Handlers must be trained to:
- store fruits and vegetables in the refrigerator at 5°C or below and above raw meat
- keep fresh produce separate from raw meat and other animal products
- use separate equipment and utensils to prepare fresh vegetables and fruit — never use the same chopping board for raw meat and salad ingredients!
- thoroughly rinse all fruits and vegetables
Seafood — especially raw and undercooked seafood — can cause a number of food-borne diseases, including listeriosis (Listeria), salmonellosis (Salmonella) and hepatitis A.
Seafood can also cause an infection called vibriosis, a food-borne disease caused by Vibrio vulnificus bacteria. Most people get infected with V. vulnificus by eating contaminated shellfish and experience mild cases of nausea and abdominal pain — but for some people, vibriosis can be a life-threatening infection.
V. vulnificus can also enter the body through open wounds, causing the flesh around the wound to die, earning it the nickname “flesh eating bacteria”.
To prevent food-borne diseases and wound infections from contaminated seafood, Food Handlers must be informed of the risks and be trained to:
- store raw or undercooked seafood in the refrigerator at 5°C or below
- cook seafood to the temperature required to destroy food-borne pathogens*
- follow best practices for preventing cross-contamination, including frequent and thorough hand washing
- wear waterproof bandages and gloves if they are handling raw seafood with open cuts or burns on their hands
*Some types of seafood are commonly served raw (e.g. oysters, mussels) in Australia. While popular, raw seafood is risky so it’s important to weigh the pros and cons of serving raw seafood in a restaurant or other food business. From a food safety perspective, offering raw seafood is not recommended.
5. DAIRY PRODUCTS
Dairy products, particularly soft cheeses and unpasteurised milk, are breeding grounds for bacteria, including Listeria and E. coli.
Listeria can have devastating consequences for pregnant women, including miscarriage, stillbirth, premature birth and life-threatening infections in newborn babies. E. coli can cause hemolytic uremic syndrome (HUS), a severe complication that recently caused 13 children in France to suffer kidney failure.
To prevent food poisoning, keep dairy products in the refrigerator at 5°C or below and follow the 2 Hour / 4 Hour rule, which states that high-risk foods like dairy products must be used or thrown out after two hours in the Temperature Danger Zone (5°C–60°C), and thrown out after four. Never use unpasteurised milk or cheese.
Food safety in Australia
The food handling tips provided above are a good start to ensuring safety in a commercial kitchen, but it’s important to make sure that everyone who handles food for the public is properly trained in food safety.
Food safety training is mandatory in Australia and most businesses are required to nominate a Food Safety Supervisor. Food Handler training and Food Safety Supervisors are minimum requirements for compliance with food safety laws in Australia.
Contact the Australian Institute of Food Safety (AIFS) for more information about food safety training, compliance with Australian food safety regulations or Food Safety Supervisor certification.
For businesses looking to enrol multiple employees in a food safety course, call our support team to set up an AIFS Business Account.