On December 2, 2024, the Food Standards Agency (FSA) and Food Standards Scotland (FSS) issued a warning, aimed at pregnant women and people with compromised immune systems, advising them to refrain from consuming smoked salmon due to the risk of contamination by Listeria monocytogenes (1,2)
1) Listeria and listeriosis, introduction
Listeria monocytogenes, according to the World Health Organization (WHO, 2015), is a pathogen exclusively transmitted by food. Listeriosis in the EU has a relatively low incidence, compared to campylobacteriosis and salmonellosis, and is nevertheless one of the most feared ‘foodborne diseases’, due to the high rate of hospitalization and high mortality.
Listeriosis can manifest itself as acute febrile gastroenteritis or – in preschool children, the elderly and immunocompromised individuals due to concomitant pathologies or immunosuppressive therapies – have a much more severe course, with septicemia, meningitis and meningoencephalitis that appear after a long incubation period (up to 90 days).
Pregnant women and unborn children are in turn exposed to serious risk since listeriosis – which may initially manifest itself in a mild form, such as gastroenteritis or flu-like syndrome – can be transmitted to the fetus via the placenta and cause premature births, mortality, meningitis or septicemia in newborns. (3)
2) Foods at risk of Listeria
The risk of Listeria contamination occurs mainly in ‘Ready-to-Eat foods’ (ready-to-eat foods with a long shelf life, >15 days, stored in the refrigerator), meat and fresh meat products, fresh cheeses, fish products (including frozen).
The smoked salmon has been at the top of the international rankings of fish products contaminated by Listeria monocytogenes for several years. (7) And this is why the food safety agencies of England and Scotland recommend adopting measures to reduce the risk of infection.
3) Smoked salmon, the necessary precautions
Smoked salmon, gravlax (marinated salmon) and smoked trout are the products that the FSA and FSS are concerned about. The reminder from the two agencies follows the recent management of a listeria outbreak, together with the UK Health Security Agency (UKHSA) and Public Health Scotland (PHS), as well as several previous alerts in recent years.
‘Smoked fish is a popular choice during the holidays and for many, with proper precautions, can be consumed safely. However, we strongly encourage those who are at higher risk to avoid fish cold smoked or cook it first until it gets hot. This will ensure the inactivation of the pathogen’.
The recommendations are aimed in particular at ‘pregnant women and those with weakened immune systems, such as people with certain pre-existing conditions (e.g. cancer, diabetes, liver and kidney disease, or anyone taking medications that can weaken the immune system (e.g. chemotherapy, corticosteroids, antibiotics)’.
Dario Dongo
Footnote
(1) The FSA and FSS remind higher-risk consumers on the risks of listeria associated with eating cold-smoked and cured fish. December 2, 2024 https://tinyurl.com/3jtdk76m
(2) Listeria. What you can do to reduce the risk of becoming ill due to listeria. FSA. August 24, 2023 https://www.food.gov.uk/listeria
(3) Silvia Bonardi, Dario Dongo. Listeria and listeriosis, an in-depth study. FT (Food Times). September 3, 2018
(4) Dario Dongo. Listeria, a dangerous pathogen out of control. FT (Food Times). August 19, 2023
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
 and Food Standards Scotland (FSS) issued a warning on smoked salmon due to the risk of Listeria monocytogenes){kind=link}