Causes and prevention of foodborne illness: everything you need to know

Foodborne illnesses are a significant public health concern, affecting millions annually because contaminated food can lead to severe health issues. This article explores the causes of foodborne illnesses, from bacterial and viral infections to parasitic invasions and chemical contaminants. It also outlines effective prevention strategies to ensure the safety of your meals. After all, we are what we eat.

Understanding foodborne illnesses: why it's a concern

A foodborne illness, commonly known as food poisoning, is an illness resulting from the consumption of contaminated food or beverages.

In the UK, foodborne illness is a significant public health issue. The Food Standards Agency (FSA) estimates over two million cases of foodborne illness occur annually in the UK, a substantial increase from previous estimates. It underscores the critical need for improved food safety practices and awareness to protect public health.

Foodborne illnesses are not just a concern for the general public or consumers. They are a critical issue that food handlers and those in the food and beverage industry must actively manage and control because contamination can occur at any point from farm to fork.

Staff in the food and beverage industry are typically required to undergo comprehensive training to ensure they understand how to prevent foodborne illnesses. 

This training covers many related topics, including proper handwashing techniques, correct cooking temperatures, and effective methods for preventing cross-contamination. There are also free resources for those in the industry or anyone interested in updating their understanding of food safety. Further, a free study guide can help you prepare for certification in food handling.

Common causes of foodborne illnesses

Bacterial contamination

One of the most common causes of foodborne illness is bacterial contamination. Bacteria such as Salmonella, Escherichia coli (E. coli), and Listeria are frequent culprits. Salmonella is often found in raw poultry, eggs, and unpasteurised milk and can cause severe gastrointestinal distress. 

E. coli in undercooked beef and contaminated water can lead to conditions like haemolytic uraemic syndrome. Further, Listeria, found in soft cheeses and ready-to-eat meats, is particularly dangerous for pregnant women, newborns, and those with weakened immune systems.

Viral contamination

Viruses are another significant cause of foodborne illnesses. For example, norovirus, commonly known as the winter vomiting bug, is highly contagious and can spread through contaminated food, water, or surfaces.

Hepatitis A, which affects the liver, can also be transmitted through food, especially shellfish harvested from contaminated waters. Both viruses can cause severe illness and lead to widespread outbreaks.

Parasitic contaminants

Parasites, though less common, still pose a risk. For instance, Giardia and Toxoplasma gondii can contaminate food and water, leading to prolonged illness. Giardia is often found in contaminated water and can cause severe diarrhoea. 

On the other hand, Toxoplasma gondii, found in undercooked meat and contaminated produce, can cause serious complications, especially for pregnant women and individuals with compromised immune systems.

Chemical contaminants

Chemical contaminants in food can also cause foodborne illnesses. Pesticides used in agriculture, heavy metals like lead and mercury, and other industrial chemicals can enter the food supply and pose significant health risks. These contaminants can lead to chronic health issues, including neurological damage and cancer.

How to prevent foodborne illnesses

Personal Hygiene

Handwashing is one of the most effective ways to prevent the spread of foodborne illnesses. Here is the recommended procedure:

1. Wet Hands: Use clean, running water to wet your hands.

2. Apply Soap: Apply enough soap to cover all hand surfaces.

3. Lather and Scrub: Rub your hands to create lather. Scrub all surfaces of your hands, including the backs, between your fingers, and under your nails. Do this for at least 20 seconds.

4. Rinse: Rinse your hands well under clean, running water.

5. Dry: Dry your hands using a clean towel or air dry them.

Handwashing should be performed at critical times, such as before handling food, after using the restroom, handling raw meat or touching potentially contaminated surfaces.

In addition, food handlers must maintain high standards to ensure food safety. It includes:

• Regular Handwashing: Frequent and proper handwashing reduces the risk of transferring contaminants from hands to food.
• Clean Clothing: Wearing clean uniforms or aprons helps to avoid transferring contaminants from clothing to food.
• Hair Restraints: Using hair nets or hats keeps hair from falling into food and reduces the risk of contamination.
• Avoiding Jewellery: Jewellery can harbour bacteria and pose a physical hazard if it falls into food.
• Health Monitoring: Food handlers should not work when ill, especially when vomiting or suffering from diarrhoea or open sores.

Safe food handling practices

Ensure you cook food to the appropriate temperature. Cooking food at the right temperature kills harmful bacteria and pathogens that can cause illness. Here are some general guidelines for proper cooking temperatures:

• Poultry (chicken, turkey): Cook it to an internal temperature of at least 75°C (165°F).
• Ground meats (beef, pork, lamb): Reach at least 70°C (160°F).
• Whole cuts of meat (beef, pork, lamb): An internal temperature of 63°C (145°F), and allow the meat to rest for at least 3 minutes before consumption.
• Fish and shellfish: Should be cooked to 63°C (145°F).
• Eggs: Should be cooked until the yolk and white are firm or to an internal temperature of 70°C (160°F) if using a thermometer.

You can use a food thermometer to ensure the food reaches a safe internal temperature. This practice helps eliminate harmful bacteria that can survive at lower temperatures.

Prevent cross contamination

Cross-contamination also allows the transfer of harmful bacteria or allergens from one surface or food to another. It can happen during food preparation, storage, or serving. To avoid cross-contamination, follow these best practices:

• Separate Raw and Cooked Foods: Always keep raw meat, poultry, seafood, and eggs separate from ready-to-eat foods such as salads, fruits, and bread. Use separate cutting boards and utensils for raw and cooked foods.
• Clean and Sanitise: Wash cutting boards, utensils, and countertops with hot, soapy water after preparing each food item. In addition, sanitise surfaces regularly to kill any remaining bacteria.
• Use Different Storage Containers: Store raw meat, poultry, and seafood in sealed containers at the bottom of the refrigerator to prevent their juices from dripping onto other foods.
• Avoid Reusing Marinades: Never reuse marinades that have been in contact with raw meat, poultry, or seafood unless you bring them to a boil first.

When shopping, always choose fresh, unexpired products, and inspect the packaging for any signs of damage or tampering. During preparation, thoroughly wash fruits and vegetables under running water to remove dirt and potential contaminants.Proper waste disposal is also important; promptly remove food waste and keep bins clean. A tidy and hygienic kitchen environment significantly reduces the risk of foodborne illnesses and promotes overall health.

Final thoughts

Preventing foodborne illnesses is far more effective and beneficial than dealing with their consequences. You can reduce the risk of contamination and foodborne diseases through simple activities like handwashing, using different cutting boards for meats and vegetables, maintaining a clean kitchen environment, and staying informed about outbreaks in your region.

However, despite the best precautions, foodborne illnesses can still occur. It is crucial to recognise the symptoms, such as nausea, vomiting, diarrhoea, and abdominal pain, and seek medical help promptly.