Listeria contamination in food, particularly in dairy products, poses a significant public health concern worldwide. Listeria monocytogenes (Lm), the bacterium responsible for listeriosis, is found widely in the environment and can contaminate food during various stages of production, processing, distribution and storage.

Here’s an overview of the situation regarding Listeria contamination in dairy products globally, focusing on Australia, and considerations for dairy processors and manufacturers:

Global Situation

Prevalence: Lm can be found in various dairy products worldwide, including soft cheeses, unpasteurised milk, and ready-to-eat foods. Contamination incidents have been reported in different countries, leading to food recalls, illness outbreaks, and occasionally fatalities.

Outbreaks and Recalls: Listeria outbreaks linked to dairy products have occurred in several countries, often associated with contaminated raw milk or insufficient processing and hygiene practices. These incidents can result in widespread illness and prompt recalls of affected products.

Regulatory Oversight: Regulatory agencies in many countries, such as the FDA in the United States and the European Food Safety Authority in Europe, have established microbiological criteria and regulations to control Listeria contamination in dairy products. These regulations typically require dairy processors to implement preventive measures, conduct regular testing and ensure compliance with hygiene and sanitation standards.

Situation in Australia:

Regulatory Framework: In Australia, Food Standards Australia New Zealand sets standards for food safety, including microbiological criteria for Listeria in dairy products. The Australian dairy industry is subject to stringent food safety requirements to prevent contamination and ensure consumer safety.

Incident Response: While Australia has experienced listeriosis outbreaks linked to various food products, including dairy, there are robust surveillance systems and response mechanisms in place to address foodborne illness incidents promptly. Regulatory authorities such as Dairysafe work closely with industry stakeholders to investigate detections, trace potentially contaminated products, and implement control measures.

Risk Management: Australian dairy processors and manufacturers maintain risk-based food safety management systems, including Hazard Analysis and Critical Control Points (HACCP) plans, to identify and mitigate Listeria contamination risks throughout the production process. This involves measures such as pasteurisation, hygienic practices, environmental monitoring, and product testing.

Considerations for dairy processors and manufacturers:

Preventive Controls: Dairy processors should implement robust preventive controls to minimise the risk of Listeria contamination, including stringent high-care hygiene and sanitation procedures, maintenance of cold chain integrity, separation of raw and processed products, and proper employee training.

Environmental Monitoring: Regular environmental monitoring in production for Listeria contamination is essential to detect and address potential sources of contamination. This may involve swabbing and testing equipment, surfaces, and air samples to ensure mitigation controls are maintained.

Product Testing: Dairy manufacturers must routinely test finished products and production environments for Listeria to verify the effectiveness of control measures.

Supplier Control: Ensuring the safety and quality of raw materials and ingredients is crucial for preventing Listeria contamination in dairy products. Dairy processors should work closely with suppliers to establish stringent measures and conduct risk assessments for incoming materials.

Traceability and Recall Preparedness: Dairy manufacturers must have robust traceability systems in place to quickly identify and recall products in the event of a Listeria contamination incident. This involves maintaining accurate records of production, distribution, and ingredient sourcing to facilitate rapid response to incidents.

In conclusion, Listeria contamination in dairy products is a significant food safety issue globally, including in Australia. Dairy processors and manufacturers must prioritise preventive measures, and implement rigorous food safety management systems and training, to mitigate the risk of Listeria contamination and ensure the safety and integrity of their products.

Creating and fostering a positive food safety culture is vital for mitigating the risk of food incidents, including the risk of Listeria. As well as reducing expenses and increasing business efficiency, food safety culture provides the basis for all people in the business to focus on food safety through shared values, beliefs, and behaviours.

Due to the nature and risk of listeria contamination in dairy products, Dairysafe has made available industry training as well as including listeria in its new FREE online learning, ‘Managing notifiable contaminants in Dairy’, to be released at the start of July 2024.