Health officials in the United Kingdom are investigating a potential outbreak of Listeria that has killed one person.

Whole genome sequencing of listeriosis samples by the UK Health Security Agency (UKHSA) has identified three cases with one death, possibly as part of an outbreak.

Patients are aged 59 or older and are from the south of England or London. One person fell sick in November 2022, while the other two became ill in February 2023.

A similar strain as the one from patient samples has also been found in some unspecified food products and samples taken from food production environments.

The Food Standards Agency (FSA) has warned people not to eat Baronet soft cheeses because they are contaminated with Listeria. In some cases, an “exceptionally high” level of the pathogen was found.

A closely genetically related strain of Listeria monocytogenes found in samples of Baronet cheese was detected in the three patients. Epidemiological investigations are continuing.

Product recall
The Old Cheese Room has recalled Baronet, Baby Baronet, and Mini Baronet Soft Cheese because of Listeria monocytogenes. Baronet is a pasteurized semi-soft cheese with a pinkish-orange rind and a pungent smell. Different pack sizes and best-before dates are affected with dates up to April 18. The latest list can be found here.

Cheese can be served sliced from deli counters. Consumers have been advised to contact the retailer they bought their Baronet cheese from to see if what they purchased was from the businesses and batches covered in the recall.

“Due to this outbreak of Listeria monocytogenes, we are urging consumers who are vulnerable to Listeria infection – including people who are pregnant and people with weakened immune systems to ensure they follow the advice in the product recall notices, which detail all of the products which may pose a risk,” said Tina Potter, FSA head of incidents.

“We are also asking people to make sure that elderly relatives who may have purchased the recalled items, and who are at particular risk, are aware of the recall and observe the advice.”

Old Cheese Room’s Response
Businesses are being advised to check whether they have been impacted by product withdrawal and recalls. If suppliers have sold onto retailers, it is vital that each retailer carries out a recall and informs their local authority, said FSA.

Any companies that have received affected products need to ensure good hygiene to prevent the risk of cross-contamination. It is possible that other cheese, if handled using the same equipment or on common surfaces, may also become contaminated, added the agency.

The Old Cheese Room said a batch that was originally tested by environmental health officers during an annual visit and that came back clear, was found to be positive for Listeria as part of retesting.

No Baronet of any size has been made since the start of March.

“We have not been told not to make Baronet by any authorities, however, it seems a sensible decision not to make any until we have found the source of the issue. As responsible cheesemakers we carry out regular cleaning, disinfecting, and swab testing of our making and ripening rooms. We have now changed our monthly testing regime to positive release, this means that we test every batch of cheese before it leaves our premises,” said a company representative.