Research and analysis

Notified cases of Salmonella Enteritidis (t5.9411 and related clusters) in England

Published 27 August 2026

Applies to England

This release provides an up-to-date count of confirmed notified cases of Salmonella Enteritidis t5.9411, t0.24068 and t5.9765 in England (as of 10:00 on 25 August 2026) and will be updated weekly.

Case number updates will be published at 9:30am on Thursdays and refer to data at 10am on Tuesday, unless otherwise specified.

Overview

Since 2014, the Gastrointestinal Infections, Food Safety and One Health (GIFSOH) division at the UK Health Security Agency (UKHSA) routinely undertakes surveillance of salmonellosis in England using whole genome sequencing (WGS). All Salmonella cultured from patients presenting to hospitals or primary care undergo WGS in England. Therefore, England undertakes more WGS than many other countries in the EU, enabling rapid detection of the emergence and investigation of new outbreaks. Given this robust surveillance system and large-scale WGS capability at UKHSA, it is likely that this contributes to higher case reporting in England compared to many other countries rather than an indication of a greater true prevalence. Despite the robust surveillance and WGS capability in UKHSA, the true number of Salmonella cases in England is likely to be greater than the numbers reported in surveillance systems given under-ascertainment in cases who may not seek healthcare due to milder symptoms.

In 2025, there were 10,406 laboratory reports of Salmonella, of which 3,104 (29.8%) were Salmonella Enteritidis (SE), making SE the most frequently reported Salmonella serovar (1). Whilst some cases of SE can be attributed to outbreaks, many cases are acquired through travel, and others are sporadic cases which do not form large outbreaks.

On 26 May 2026, UKHSA identified an increase in the number of cases of SE caused by a single strain using WGS (UKHSA designation SE t5.9411). UKHSA initiated an outbreak investigation, working with public health and food safety agencies in the UK and Devolved Administrations, and the Animal and Plant Health Agency (APHA) to identify additional cases, and consider potential sources of the outbreak to enable control measures to be implemented. In June and July 2026, there was an increase in case reporting which led to intensified investigations. Further information on the t5.9411 cluster can be found in the published UKHSA Health Protection Report (2).

Since initiating the investigation into the SE t5.9411 cluster, UKHSA has also identified an increase in 2 other SE clusters (t0.24068 and t5.9765). These 2 additional clusters are genetically distinct to the t5.9411 cluster but are part of the wider family of SE which have seen increased case reporting from June 2026. The genetic relatedness of these clusters, alongside the epidemiological and food exposure information known to date, suggests that these outbreaks could all be associated with imported eggs and are therefore being investigated in parallel. The t0.24068 cluster was first investigated in 2025 and has re-emerged, with an increase in case reporting from June 2026. Further information on the t0.24068 cluster can be found in the published UKHSA Health Protection Report (3). Figure 1 shows cases in the 3 outbreak clusters (t5.9411, t0.24068 and t5.9765) over time against the background rate of all Salmonella in England.

Figure 1. Confirmed cases of SE t5.9411, t0.24068 and t5.9765 by week of sample date in 2026, against all Salmonella reported by the Gastrointestinal Bacteria Reference Unit (UKHSA), England

The European Centre for Disease Prevention and Control (ECDC) has also reported an ongoing multi-country outbreak of SE, with the United Kingdom (UK) accounting for 61% of the 341 confirmed cases reported between May 2025 and August 2026 from SE t5.9411 (4). Cases linked to the outbreak strain have also been identified in Austria, Belgium, Denmark, France, Germany and the Netherlands, with the Netherlands reporting 31% of the 341 confirmed cases. New infections were reported in early August 2026, indicating that the outbreak remains ongoing in the EU.

Confirmed case definitions

t5.9411

A case of SE resident in England belonging to the UKHSA designation 1.2.3.18.5849.9411 reported by UKHSA’s GBRU since 11 August 2025 (earliest sample date for a case in this cluster).

t0.24068

A case of SE resident in England belonging to the UKHSA designation 1.2.3.18.180.180.24068 or within an absolute genetic distance of 5 Single Nucleotide Polymorphisms reported by UKHSA’s GBRU since 27 May 2025 (earliest sample date for a case in this cluster).

t5.9765

A case of SE resident in England belonging to the UKHSA designation 1.2.3.18.4050.9765 reported by UKHSA’s GBRU since 27 January 2026 (earliest sample date for a case in this cluster).

Notified cases

The increase seen in these 3 clusters of SE is part of a wider context of Salmonella transmission. Between 18 August and 24 August 2026, 260 non-typhoidal Salmonella isolates were identified at UKHSA’s GBRU, 122 (46.9%) of these isolates were identified as SE and 36 (13.8%) are part of these 3 outbreak clusters. The remaining cases of SE that are not associated with these 3 outbreak clusters are either associated with travel, are part of other clusters, or are sporadic cases.

t5.9411

As of 10:00am on 25 August 2026, the UKHSA has been notified of a total of 259 cases in the t5.9411 cluster in England. The sample dates of cases range from 11 August 2025 to 08 August 2026. In the past 4 weeks (27 July 2026 to 24 August 2026), 189 cases have been reported in England.

Figure 2. Confirmed cases of SE t5.9411 by week of sample date, England (n=252)[note 1]

Note 1: sample dates are not known for the remaining 7 cases.

Cases distributed across all 9 regions in England are shown in Table 1.

Table 1. Rate of cases of SE t5.9411 per 100,000 population by region of residence, England since 11 August 2025

Region	Rate per 100,000 population
North East	1.42
North West	0.19
Yorkshire and Humber	0.79
East Midlands	0.14
West Midlands	0.10
East of England	0.67
London	0.79
South East	0.38
South West	0.02

Cases range in age from 0 years to 90 years (median 30 years) and 51.0% of cases are male.

Of the cases with information available (n=149), 41 cases (27.5%) have been admitted to hospital and there has been one death associated with this outbreak cluster.

t0.24068

As of 10:00am on 25 August 2026, the UKHSA has been notified of a total of 177 cases in the t0.24068 cluster in England. The sample dates of cases range from 27 May 2025 to 5 August 2026. In the past 4 weeks (27 July 2026 to 24 August 2026), 18 cases have been reported in England.

Figure 3. Confirmed cases of SE t0.24068 by week of sample date, England (n=175)[note 2]

Note 2: sample dates are not known for the remaining 2 cases.

Cases distributed across 8 of the 9 regions in England are shown in Table 2.

Table 2. Rate of cases of SE t0.24068 per 100,000 population by region of residence, England since 27 May 2025

Region	Rate per 100,000 population
North East	0.15
North West	0.03
Yorkshire and Humber	0.07
East Midlands	0.04
West Midlands	0
East of England	0.61
London	1.03
South East	0.35
South West	0.03

Cases range in age from 0 years to 92 years (median 29 years) and 51.4% of cases are female.

Of the cases with information available (n=27), 12 cases (44%) have been admitted to hospital.

t5.9765

As of 10:00am on 25 August 2026, the UKHSA has been notified of a total of 38 cases in the t5.9765 cluster in England. The sample dates of cases range from 27 January 2026 to 29 July 2026. In the past 4 weeks (27 July 2026 to 24 August 2026), 6 cases have been reported in England.

Figure 4. Confirmed cases of SE t5.9765 by week of sample date (where available), England (n=35)[note 3]

Note 3: sample dates are not known for the remaining 3 cases.

Cases distributed across 8 of the 9 regions in England are shown in Table 3.

Table 3. Rate of cases of SE t5.9765 per 100,000 population by region of residence, England since 27 January 2026

Region	Rate per 100,000 population
North East	0.26
North West	0.08
Yorkshire and Humber	0.02
East Midlands	0.02
West Midlands	0.02
East of England	0.09
London	0.14
South East	0.04
South West	0

Cases range in age from 2 years to 87 years (median 32 years) and 52.6% are male.

Of the cases with information available (n=14), 5 cases (36%) have been admitted to hospital and there has been one death associated with this outbreak cluster.

Data quality assurance

Data quality was assured through automation, where possible, and via a manual checking process undertaken by a second person.

Further information and advice

Latest news and information

Further information on Salmonella can be found on the NHS website and UKHSA website.

References

1. Non-typhoidal Salmonella data 2016 to 2025

2. HPR volume 20 issue 8: news (18 August 2026)

3. HPR volume 19 issue 11: news (4 December 2025)

4. Communicable disease threats report, 15 - 21 August 2026, week 34