Pregnant women were informed today that they should not eat ready-to-eat cold-smoked or salted salmon because of the listeria risk.
Food safety chiefs also issued the same warning to millions of Britons with diabetes, cancer and liver disease.
Ssmoked salmon and trout are more likely to contain the bug, which can be life-threatening to those at risk because the food isn’t fully cooked during production.
The Food Standards Agency recommended cooking them until piping hot, to kill any listeria that may be lurking.
FSA bosses also urged the elderly to be “aware of the risks.”
Mothers-to-be, along with cancer, diabetes and liver disease patients, should avoid the food for fear that they will become seriously unwell if the products are contaminated with listeria
It means items like smoked salmon, smoked trout and sushi are no longer on the menu unless they are cooked until piping hot, according to the Food Standards Agency.
Listeriosis, the infection caused by listeria, can cause serious illness, hospitalization and, in severe cases, death in those most at risk.
Pregnant women are at risk of miscarriage and severe sepsis, while their newborn baby may develop meningitis.
However, most people only have short-term complaints, such as fever, aches, chills, vomiting and diarrhoea.
NHS officials are already telling pregnant women to avoid cold-smoked salmon and salted fish products, along with uncooked soft cheeses, unpasteurised dairy products and undercooked foods.
The reminder follows a joint risk assessment by the FSA and their equivalent body in Scotland.
It came into use in response to an ongoing outbreak, which began in 2020 and is related to ready-to-eat fish.
There have been 19 confirmed cases of listeriosis linked to the fish products – the most recent of which was in June – and four deaths in the UK since 2020.
The watchdogs found that the risk of pregnant and vulnerable Britons contracting listeriosis from the products is generally low.
However, if they catch the bug, they can become seriously unwell.
They advised pregnant women, people with weakened immune systems and anyone taking medications that can weaken the immune system — including cancer, diabetes, liver and kidney disease patients — to avoid the food.
It was previously advised that it is fine for risk groups to eat these foods when they are cooked. But now it tells the vulnerable to ‘avoid’ the products -‘but if you choose not to follow this advice, make sure you cook it right’.
Since the risk of serious illness from listeriosis increases with age, the FSA also advised the elderly to be wary.
Professor Robin May, Chief Scientific Adviser to the FSA, said: ‘Our risk assessment shows that there is still a health risk associated with eating cold smoked fish for specific groups of vulnerable people.
‘In light of the risk assessment, we advise these consumers to avoid ready-to-eat cold-smoked and salted fish products.
‘If you belong to the group of people who are more at risk of a listeria infection and you decide to consume these products, we strongly advise you to steam them first.
“This ensures that any listeria present in the product is killed before it is eaten.”
‘Cold smoked’ fish is normally labeled as ‘smoked’ fish on the packaging.
Ready-to-eat cold-smoked fish usually comes thinly sliced and can be eaten cold. It can also be found in sushi.
Once properly cooked, the smoked fish is safe to eat and can be served immediately, or served cold after chilling in the refrigerator.
If cold-smoked fish is added to dishes such as cooked pasta or scrambled eggs, the FSA says it’s important to cook it first. This is because cooking through will not heat the fish to a temperature high enough to kill any listeria present.
Dr. Gauri Godbole, consultant microbiologist at UKHSA, said: ‘Although smoked fish carries a higher risk of carrying listeria, the overall risk to the population is very low.
However, some people are more likely to develop a serious infection, including those who are pregnant and those with weakened immune systems. The risk also increases with age.’
The FSA noted that cases of listeriosis from smoked fish generally remain rare and those who have recently eaten the food should only seek NHS care – by calling 111 or their GP surgery – if they are in a high-risk group and have symptoms of develop listeriosis.