Listeriosis – guidance for food businesses
This guidance is specific to Listeria monocytogenes control and is designed to set out the steps you need to take, as a food business, to control the risk of listeriosis. The reason for this Guidance Note is that there has been increased cases of listeriosis in the UK.
What is it?
Listeriosis is a disease caused by the bacterium Listeria monocytogenes (L. monocytogenes). It is widespread in the environment and can be found in vegetation, raw foods, soil, water and animal faeces. It can live in food processing environments and, because it is covered in a slime, it can attach to surfaces and can be difficult to remove and resistant to cleaning and disinfection. Food which comes into contact with it can become contaminated.
What harm can it do?
Groups vulnerable to Listeriosis include people with weakened immune systems, pregnant women and the elderly. The effects include a high hospitalisation and fatality rate compared to infections with other bacterial pathogens. Effects can range from mild flu-like symptoms to bacteraemia, septicaemia, meningitis and, in pregnant women, miscarriage and stillbirth.
Some types of food associated with listeriosis outbreaks include:
- Fish; smoked fish, cooked shellfish
- Meat; pate, cooked meats/poultry, cured meats
- Pasteurised/unpasteurised cheeses; soft blue veined cheeses, mould-ripened soft cheeses
- Prepared foods e.g. pre-packed sandwiches, salads, cut fruits, including melon.
Growth of Listeria monocytogenes (L. monocytogenes)
Unlike most other pathogenic bacteria, L. monocytogenes has the potential to grow at low temperatures, including refrigerator temperatures. It can grow in low oxygen environments.
L. monocytogenes can survive freezing and is salt tolerant.
Implement a personal hygiene policy to ensure staff follow effective personal hygiene practices, such as:
- Handwashing controls.
- Staff to wear clean, and where appropriate, protective clothing.
- Food handlers preparing ready to eat (RTE) foods should not travel to their place of work in their protective clothing.
- Make sure work clothes are properly laundered for example on hot wash.
- Minimise handling of chilled RTE foods prior to service.
Cleaning and disinfection
- Make sure your work premises is well maintained, cleanable and clean (and disinfected where appropriate). This will minimise the risk and remove potential sources of L. monocytogenes contamination.
- Where possible disinfect food contact equipment by using the dishwasher on a hot setting cycle, following the manufacturer’s instructions.
- Use separate cleaning equipment for raw and RTE preparation areas to limit spread of contamination.
- Effective cleaning and disinfection is important for all food pathogens but points to be aware of in relation to L. monocytogenes are:
- Regular two-stage cleaning and disinfection
- stage 1: general cleaning using a detergent and
- stage 2: disinfectant.
- It is important to ensure food contact surfaces are cleaned appropriately and to avoid the formation and build-up of biofilms. If food comes into contact with a biofilm during food preparation, it can become contaminated.
- Keep moisture levels in food areas to a minimum. Repair damaged and poor floor drainage in kitchens, damaged flooring and areas where water can pool can be a reservoir for L. monocytogenes biofilms.
- Avoid accumulation of condensation in refrigerators and blast chillers, as this can create favourable conditions for biofilms, which may be distributed via dripping or moist air blown through the units.
- L. monocytogenes can grow in refrigerated storage. If you minimise the shelf life you will limit the opportunity for L. monocytogenes to grow to harmful levels.
- Follow manufacturer’s instructions for use-by dates and storage.
- Use foods within their use-by date and follow manufacturer’s instructions.
- Where products are made on site ensure the shelf life of the finished product, for example, sandwiches, does not exceed that of any of the ingredients. (Note: It is against the law to use or supply food past the manufacturer's use-by date).
- Set an appropriate shelf life, where foods are made on site, for example, a maximum chilled shelf life would be day of production plus 2 days should be applied, unless evidence of shelf life studies is provided to prove otherwise.
The management of appropriate chill temperatures is an essential food safety control for L. monocytogenes.
- Maintain the cold chain.
- Minimise the time that food spends out of the cold chain (during preparation, delivery, service etc).
- Some manufacturers may set a storage temperature lower than 5°C and these instructions must be followed.
- Deliveries of chilled RTE food should be placed in refrigerated storage promptly. Make sure you follow the ‘4 hour rule’ where rules provide an exemption for certain foods to remain out of temperature for one period of up to four hours for display and service purposes.
What do food businesses need to do?
- Food safety law requires all food business operators to have in place arrangements to control Listeria.
- Safer Food, Better Business (SFBB) are food safety management packs for small catering and retail businesses, residential care homes and childminders. Food businesses will be expected to control the risk of Listeria and other food safety risks in these types of businesses if the packs are fully implemented in food establishments that comply with the rules. Businesses do not have to use SFBB and can use other food safety management systems to control Listeria. SFBB packs can be ordered from our Safer food better business page.
- SFBB is not suitable for some types of business e.g. fish smokers and processors, manufacturers, butchers, fishmongers and bakers. These types of businesses should ensure they are run from food establishments that comply with the rules and have food safety management systems based on the Hazard Analysis and Critical Control Principles (HACCP) that:
- Look closely at what the business does, what could go wrong and what risks there are to food safety, including Listeria.
- Identify any critical control points the areas the business needs to focus on to ensure those risks are removed or reduced to safe levels.
- Decide what action to take if something goes wrong.
- Make sure procedures are being followed and are working.
- Keeping records to show procedures are working.
For further information on HACCP, please visit the Food Standards Agency’s website.