The UK Health Security Agency (UKHSA) is investigating a listeriosis outbreak involving five illnesses and three deaths. Desserts supplied to UK National Health Service (NHS) healthcare facilities are being considered as the potential vehicle of illness and have tested positive for Listeria monocytogenes, but have not yet been confirmed as the cause of the outbreak.

The five outbreak patients, ranging in age from 68–89, all had underlying health conditions and were already staying in hospitals at the time of their infection by L. monocytogenes. The patients were treated between May and December 2024, and were located in Yorkshire and the Humber (two patients), the North West of England (one), the West Midlands (one), and Wales (one).

Of the three people who died, one was recorded as listeriosis as the cause of death. The other two people were infected with L. monocytogenes at their time of death. The outbreak was discovered during routine surveillance conducted in February 2025 at an NHS hospital in the South West of England.

The UK Food Standards Agency (FSA) is looking into Cool Delights-brand desserts, supplied to NHS hospitals and care facilities, as the potential vehicle of illness. Although some of the desserts—a chocolate/vanilla mousse and a strawberry/vanilla mouse—tested positive for L. monocytogenes, the level of contamination was below the legal threshold for what is considered to cause illness in healthy, adult people. Out of an abundance of caution, the desserts have been removed from the supply chain while investigations are underway.

Listeriosis Also Strikes Healthcare Facilities in the U.S.

Similarly, in the U.S., an outbreak investigation is ongoing for a string of listeriosis illnesses linked to nutritional shakes served at healthcare facilities. A total of 38 people (34 of whom lived in long-term care facilities or were staying in a hospital at the time of illness) and 12 deaths have been reported in 21 states. Sysco Imperial and Lyons ReadyCare Frozen Supplemental Shakes were identified as the vehicle of illness and have been voluntarily recalled.

L. monocytogenes is particularly life-threatening to vulnerable groups who are likely to be residents of long-term care facilities and hospitals, such as the elderly and newborns, and those who are immunocompromised or pregnant.