The UK Health Security Agency (UKSHA) has launched an investigation into an outbreak of Salmonella enteritidis, after the organisation released data showing an increase in the number of cases recorded this year.
Initial findings suggest that this may be linked to eggs imported from outside the UK, the UKHSA said in a statement, but there is no identified link to UK-produced eggs or poultry.
The agency declared a national outbreak of the Salmonella strain in the UK on 18 August 2026.
It said that 207 cases were confirmed between 11 August 2025 and 1 August 2026, with the majority reported in 2026. Of those with the infection, 38% were admitted to hospital and one person died.
UKHSA has now initiated an investigation into the outbreak to confirm the source of the illness.
Extensive epidemiological and food chain investigations are ongoing to identify the source and origin of the contamination responsible for illness, it said.
UKHSA said that the 2026 outbreak of S. Enteritidis had been found to be “phylogenetically linked" to a previous outbreak from 2025, which was found to be due to imported eggs.
Brendan Wren, Professor of Microbial Pathogenesis at the London School of Hygiene & Tropical Medicine (LSHTM), commented that the infection was of most risk to the elderly or immunocompromised people.
"Salmonella enteritidis causes severe diarrhoea and can be fatal in the elderly or immunocompromised individuals. It is readily transmitted through the handling or consumption of food.
“Using DNA fingerprinting the outbreak of at 200 cases appears to be from a single source. The most likely source is from the consumption of eggs or egg-related products such as mayonnaise. The outbreak control team at the UKHSA are actively investigating the source and routes of transmission of the outbreak."
S. Enteritidis is the most common Salmonella type in England and the leading cause of salmonellosis in people, spread via consumption of contaminated food (including eggs, poultry, meat, unpasteurised dairy and fresh produce), contact with the environment, or person-to-person transmission.
Symptoms of salmonella infection include diarrhoea, stomach cramps and sometimes vomiting and fever.
Salmonella most often causes a self-limiting gastroenteritis, while immunocompromised individuals and those in vulnerable groups (young children and older adults) may experience more severe illness, such as blood stream infections, infection of metastatic sites, sepsis and multiorgan failure.
