The Food Standards Agency (FSA), Food Standards Scotland (FSS), and the UK Health Security Agency (UKHSA) are reinforcing their advice to vulnerable groups of consumers in relation to the risks of Listeria monocytogenes infection linked to ready to eat smoked fish.

The advice to those who are over 65, pregnant or have weakened immune systems is that they should ensure that ready to eat smoked fish is thoroughly cooked before they eat it. ‘Ready to eat smoked fish’ refers to chilled smoked fish products that would not normally be cooked at home before being eaten.

This is due to an ongoing Listeria outbreak linked to smoked fish that Food Alert reported on back in April.  There have been 14 linked cases and three elderly people have died.

Listeria is of concern in chilled, ready to eat foods that do not require further cooking, such as smoked fish and it has also been listed as a high-risk product which should be thoroughly cooked before being eaten by anyone in a high-risk group.

General principles for reducing the risk from Listeria in chilled foods include:

• Prevent foods from becoming contaminated with L. monocytogenes
• Strict controls on appropriate shelf life and effective cold chain management must be applied
• Storing chilled ready to eat foods cold at 5⁰C or below
• Thorough cooking of food to kill Listeria monocytogenes
• Good personal hygiene

Businesses that serve smoked salmon

• Only use reputable approved suppliers and obtain the supplier specification for the product
• Ensure deliveries arrive below 5⁰C and check and record the temperature on delivery
• Always store smoked fish cold at 5⁰C or below
• Never use beyond the shelf life of the product
• Follow the manufacturer’s instructions on use by after opening and do not exceed this (some state within 24 hours, but other state 2-3 days)
• Once opened, cover and store below 5^oC or according to manufacturer’s instructions
• Consider menu advice for vulnerable groups to avoid.

Smoked salmon production

Smoked salmon production is a complex process for which you would need a detailed HACCP and sampling programme. Please contact Food Alert for advice.

For clients that are producing cold smoked salmon and vacuum packing, there are two main organisms of concern, Clostridium and Listeria. These can grow in all ready to eat foods that are vacuum packed but fish is especially vulnerable because Listeria, as an environmental organism, will be present on and in the raw fish.

• In order to control the growth a controlling factor is required which for cold smoked fish would usually be salt content that exceeds 3.5 % in the aqueous phase.
• Salt preserves smoked fish by reducing the moisture content but this needs to be validated in a laboratory to ensure it consistently reaches this level throughout the fish. The product must be stored below 5 °C.
• Alternative control factors include pH < 5.0 or Water Activity (Aw) under 0.97.
• Testing of the processing environment must be undertaken for foods such as fish that support the growth of L. monocytogenes.
• Verification of effective cleaning and sanitation (e. g. using swabs and microbiological testing or ATP detection equipment) is required to ensure that there is not establishment of persistent strains of L. monocytogenes in the factory.
• Shelf-life studies for foods with shelf lives less than 5 days are not required. However, they must comply with the 100 cfu/g  monocytogeneslimit, so sampling is required
• If you cannot provide evidence substantiating the shelf life you have given a food, you must demonstrate that monocytogenes is absent at the end of manufacture. You will need to establish a sampling programme and select suitable locations in which to sample.
• In addition, there are rules in place for the use of farmed and wild fish. For wild fish and farmed fish when the FBO cannot guarantee absence of parasites (a supplier certificate should be available as evidence) a control measure must be assured by freezing of fish for 24 hours at ≤ -20° C’ or-35° C for not less than 15 hours in all parts of the fish. Due diligence records must be kept and Food Alert can supply these.

If you require any further information or advice or assistance with microbiological sampling, please contact Food Alert Advice Line on advice@foodalert.com or 0844 445 7412.