Listeria can survive at 'freezing temperatures'

RTÉ News​

3 days ago

The former CEO of the Food Safety Authority of Ireland has said that listeria can survive at "freezing temperatures," following a precautionary recall notice over ready-to-heat meals after an outbreak of the infection.
Adjunct Professor at UCD Institute of Food and Health Alan Reilly, said listeria monocytogenes is "unique in that it can survive at low temperatures... even freezing temperatures".
Therefore, he said for the list of foods subject to the recall, "that rely on chilled storage for fairly long periods, listeria monocytogenes would be the number one pathogenic bug that you have to look out for".
An adult died with a confirmed case of listeria infection, the FSAI confirmed yesterday.
The FSAI said that it had
Listeria can enter the food chain from contaminated water, through soil, through animal contact during agricultural practices and can contaminate foods and spread to surfaces.
Following this it can spread through contaminated equipment or the hands of food handlers into the processed environment.
Professor Reilly said listeriosis is a "bacterium," but some "listeria monocytogenes, they are pathogenic, and they are "probably one of the most serious forms of food-borne illness you can get".
Speaking on RTÉ's Today with Philip Boucher Hayes, he said it causes two types of illnesses, a "non-invasive" kind, "you could nearly call it routine food poisoning," and the other is an "invasive" kind, and this invasive type is "the real killer".
"You get things like septicemia, blood poisoning, it invades a lot of organs and so on...and meningitis, it can cause spontaneous abortion in pregnant women.
"And that form is the real killer," he said.
However, he added that there is "not a lot" of listeriosis in the food chain.
In 2024, there were less than one case per 100,000 people in the EU, compared with 46 cases per 100,000 people of campylobacter and 18 cases per 100,000 of salmonellosis, he said.
A lot of work is done to keep listeriosis out of the food chain, Prof Reilly said.
It would "probably " enter a food processing plant on "raw materials" such as vegetable matter, uncooked meats and "establishes itself" in the food processing environment, such as on a "biofilm" on a conveyor belt, where listeria will survive, he said.
He said one outbreak in Canada some 17 years ago, which generated 55 cases, from which there were 22 fatalities, was tracked down to a meat slicer, which then contaminated deli meats and led to "one of the most serious outbreaks".
"After that outbreak, in 2008, the world woke up to listeria monocytogenes", he said.
Symptoms of listeria
The FSAI said a National Outbreak Control Team is investigating an extensive outbreak of listeria linked to a precautionary food recall of ready-to-heat meals.
Products from Tesco Finest, The Happy Pear, SuperValu Signature Taste, and Centra Freshly Prepared are among a range of more than 200 affected ready meals included in the recall.
Consumers are being advised to check their freezers for the implicated products and dispose of them.
Speaking about listeria, Deputy Medical Director of the Irish College of GPs Dr Suzanne Kelly said those who should be concerned about the disease are pregnant women, small babies, older people and the immunocompromised.
She said that for the vast majority of healthy adults, this isn't going to cause a major problem as there is a lot of exposure to listeria, but it clears easily in people day to day.
She said symptoms of listeria would be having a temperature, feeling achy, experiencing nausea or diarrhea.
She added that the first thing to do if you have symptoms is to schedule an appointment with your GP for an assessment but tests for listeria have to be done in a hospital setting.
She said that she has never seen it as a GP in 20 years but it's most worried about for pregnant women who are at high risk of having a miscarriage, or passing the disease onto their baby.
"We rarely ever see it," she said, adding that the disease must be detected through a blood test, or through spinal fluid.