The elderly and pregnant should not eat smoked salmon to avoid the risk of listeria poisoning. There is a tiny report in The Times newspaper today about a raw fish health alert and it concerns specifically pregnant women and elderly people who should not eat raw smoked fish because of the risk of listeria as advised by the experts. There have been eight listeria cases in England and Scotland since January 2022 according to the Food Standards Agency and the UK Health Security Agency. So, I decided to dig around a bit to see what was going on.
The first question that I had was whether sushi includes raw smoked fish. It certainly includes raw fish, but sushi also includes foods that are not necessarily raw. It is sashimi which is just sliced raw fish sometimes tipped in sources. Sushi includes sashimi. It’s a bit complicated but if listeria can be found in smoked raw fish it can be found in raw fish which is confirmed by a study published on the National Library of Medicine called: “Incidence of listeria species in seafood and seafood salads”.
The scientists looked at 128 samples of seafood in Iceland; specifically in an Icelandic market where raw, smoked and dried fish, frozen shellfish and shrimps were sold as well as several fish salads. These products are eaten without being cooked.
They found that listeria was present in 56% of the samples of raw fish, 29% of the smoked fish, 9% of the shrimps and 32% of the salads. The shellfish or dried fish did not contain listeria. All the products had been processed and packed in Iceland for the domestic market. They concluded that “It is suggested that consuming certain fish products and fish salads may form an additional risk factor for listeriosis in humans”.
The concern is this: elderly people have a weak or compromised immune system which makes them more vulnerable. Pregnant women are more vulnerable because they are carrying an unborn baby and the baby is vulnerable. Therefore, the advice is not to eat these raw fish products. When you cook products, you kill the listeria which is a bacterium.
Listeriosis in pregnancy can cause miscarriages and severe sepsis (blood poisoning) or meningitis in new-born babies. People over 65 often have underlying medical conditions such as cancer or kidney disease. They are often taking medications which can weaken the immune system. Listeriosis can cause meningitis and life-threatening sepsis in this group of people as well.
The listeria bacterium is often found in the environment i.e., in the soil and it can contaminate and grow on food even when in a fridge. Other foods linked to listeria are pâté, cured meats and some soft cheeses such as camembert and brie.
There is a story in the news about a woman who died in hospital after eating a chicken mayo sandwich at St Richard’s Hospital in Chichester. She was discharged on May 3rd, and felt weak when recovering at home in Chichester, Kent but her family had no idea it was the listeria causing the symptoms. She was rushed to hospital and tests revealed listeria poisoning. She died two weeks after returning to hospital. A sad example of an elderly woman in her 80s dying prematurely of listeria poisoning.
So, listeria is potentially in chicken mayo sandwiches as well as raw fish. I’m going to stop eating smoked salmon which I particularly like.
Below are some more pages on human behaviour.
