On 20/02/2025, the Food Standards Agency issued a food alert relating to the possible presence of listeria monocytogenes in identified cheese products sold in the UK and NI. Listeria, whilst not the most common pathogenic bacteria found in food, is certainly one of the most dangerous. Flu-like symptoms can include high temperature, muscle ache or pain, chills, feeling or being sick and diarrhoea. Listeria infection can lead to serious complications requiring hospitalisation including meningitis and sepsis, and can cause death.

Understanding Listeria

Listeria monocytogenes is a group of approximately 13 variations of pathogenic bacteria, which cause listeriosis in humans. The pathogens typically thrive in soil, water and faeces. They are notoriously hard to control because they survive a wide range of conditions, including cold temperatures and environments with no oxygen. Listeria pathogens can be denatured through cooking at suitable times and temperatures. Therefore the greatest risk of listeria to consumers is via ready-to-eat or chilled foods that are eaten without cooking.

Vulnerable groups

Listeria can be particularly dangerous to vulnerable groups including:

• pregnant women
• new born babies
• older people
• people with conditions or undergoing treatments that weaken their immune system

Follow the NHS guidance if you believe you or someone you know has listeriosis, particularly within these vulnerable groups.

What to do - consumers and retailers

Check the products listed within the FSA recall notice, and return to the places you purchased - retailer, wholesaler or direct from the manufacturer. The FSA notice has received considerable attention but keep the website handy in case needed for reference. Currently, the alert relates to cheese products for sale in Tesco, Spar and Lidl NI, but may be extended by the FSA.

Prevention of listeria in food manufacture

Because of the characteristics of listeria, manufacturers must pay particular attention to risk assessment of this pathogen. In particular, ready to eat foods present a particular risk, as no cook process will take place after purchase. A report by the Chilled Food Association (CFA) has produced specific guidance for the management of Listeria monocytogenes during food production of ready to eat foods.

The process detailed by the CFA combines a thorough risk assessment and HACCP process with a rigorous testing regime. As many raw ingredients used in food manufacture may have come into contact with listeria, control here is crucial.

Prevention of cross contamination

Although the process includes testing raw ingredients for listeria, there is an acceptance that the pathogen is nevertheless likely to enter the facility. Therefore, every step must be taken to control its growth and prevent cross contamination throughout production. Key elements highlighted to eliminate cross contamination of listeria within a manufacturing environment include:

• Product design - understand the key safety risks associated with the product type, and how to produce, package and store safely
• Raw material Risk Assessment - consider the risks inherent within ingredients and how to store appropriately
• Premises design and layout - considerations include zoning, workflow and reducing human vehicles of contamination
• Equipment - consider ease of cleaning and sanitisation
• Building work / renovations / maintenance - ensure any maintenance does not cause further risk of contamination
• Waste management - timely and effective disposal of waste to prevent recontamination
• Cleaning and disinfection - of the whole production environment, paying particular attention to areas likely to harbour moisture and dirt
• Personal hygiene - handwashing and correct use of PPE
• Removal of water - humidity and ventilation to restrict pathogenic growth
• Storage - of ingredients and finished food products, before, during and after production
• Training - see below
• Temperature control - both during processing to denature pathogens and before and after to prevent growth. Especially important in ready to eat foods.

Testing

The CFA also recommend a rigorous testing programme as part of listeria control in a production environment. They point out that occasional positive results are not necessarily a negative, but can be a sign that monitoring is working effectively, and can be key to identifying problem areas and weakness in the process

Visual inspections and swabbing are useful in identifying potential problem areas and helping to reinforce staff training. The most important part of testing however, is a thorough sampling protocol, that begins with raw ingredients and continues throughout production, packing, storage and delivery. An action plan should be in place, and implemented upon discovery of pathogens above the levels dictated by EU Reg 2073/2005, as these are considered potentially harmful to health.

Food safety culture

Creating a strong food safety culture - the acceptance that food safety is the responsibility of all - is key to embedding the necessary systems and processes in a food business. A crucial part of this is providing good safety training at an appropriate level for every role.

The Safer Food Group offer accessible, engaging online training with a focus on practical knowledge that can be easily brought into the workplace. Courses include:

Level 2 Food Hygiene (Manufacturing)

This course equips food handlers with the basic knowledge they need to understand the importance of good food hygiene in a food production environment. It teaches practical skills including prevention of cross contamination, good personal hygiene and the importance of correct times and temperatures. It also informs food handlers of their personal legal responsibilities regarding food safety.

Level 2 HACCP

A comprehensive risk assessment process and resulting preventative measures are a crucial step in creating a safe food production environment. The Level 2 HACCP course introduces these principles and teaches all workers their role in upholding HACCP principles in their workplace.

Level 3 Food Supervisor

The follow-on course from Level 2 Food Hygiene, Level 3 Food Supervisor addresses the principles of food safety in greater detail. It address the science of food hygiene in a clear and straightforward way, including a breakdown of various food poisoning pathogens. It also introduces some key principles of team management for those workers new to a supervisory role.