England had 428 notified cases in the Salmonella Enteritidis t5.9411 cluster by 10am on 6 October, 15 more than in the previous weekly report. The latest surveillance release also records 102 cases in the four weeks from 8 September to 6 October. The figures describe confirmed notifications available to investigators, not every infection in the community.
What the latest count shows
The cases’ sample dates range from 11 August 2025 to 22 September 2026. The 428 is a cumulative count for the t5.9411 cluster in England; the 102 is the subset reported during the specified recent four-week period. They are not separate estimates of people currently ill, and the weekly increase of 15 should not be mistaken for the total number of infections acquired in that week.
Salmonella is identified in laboratory samples, and the cluster designation is based on whole genome sequencing. All Salmonella cultured from patients presenting to hospitals or primary care in England undergo this sequencing. It helps public-health teams recognise closely related infections, but case reporting takes time. The release says there is usually a one-to-two-week lag between a sample date and confirmation for these figures, while confirming whether a case belongs to an outbreak can take three to four weeks. Earlier weeks may therefore be revised.
The surveillance count is also not a full measure of illness. People with milder symptoms may not seek healthcare, and the release notes that the true number of Salmonella cases is likely to be higher than those captured in reporting systems. Its separate estimate of 336 non-typhoidal Salmonella isolates identified in the week from 29 September to 6 October is a laboratory measure across types, not an additional count of this particular cluster.
Three clusters under investigation
Investigators are examining three genetically distinct Salmonella Enteritidis clusters in parallel: t5.9411, t0.24068 and t5.9765. UKHSA says their genetic relationship, together with epidemiological and food-exposure information available so far, suggests the outbreaks could be associated with imported eggs. This remains an investigative possibility rather than a confirmed source or a finding that a particular supplier or product caused the illnesses.
The week 40 release counted 194 cases in the t0.24068 cluster, unchanged from the previous report, and 44 in t5.9765, one more than the previous week. Their recent four-week counts were eight and two respectively. These figures help put the larger t5.9411 total in context, but the three clusters are not interchangeable: they have different genetic designations and case definitions. A rise in one does not by itself establish a common food exposure for every case in the others.
The investigation began after an increase in t5.9411 infections was identified in May 2026. Two further increases prompted parallel investigations. The findings on possible imported eggs are based on information gathered to date; targeted evidence and continued case follow-up are needed to test the hypothesis. An earlier public update similarly described an imported-egg link as provisional and said the exact causes had not been identified.
Geography and interpreting risk
Cases in the t5.9411 cluster have been recorded across all nine English regions. The cumulative rate for London is 1.30 per 100,000 population. It is a rate of reported cases among residents since the first sample date in the cluster, not a prediction of an individual’s chance of infection or a live measure of current transmission. The rate also differs markedly between regions, so a national total alone does not describe the local pattern.
Among the t5.9411 cases with hospital-admission information available, 72 of 271 had been admitted. That denominator matters: the figure is not 72 out of all 428 cases, because the relevant information was available for only 271. One death has been associated with this cluster. These surveillance details indicate why the investigation matters, but they do not show that every infection is severe; Salmonella can cause mild illness, while some people are at greater risk of serious disease.
For now, the central message is that the confirmed notified count has continued to rise while the suspected food-source link remains under investigation. The weekly totals will be revised as delayed samples and case information become available. The data should therefore be read as a carefully defined snapshot, not a final tally or proof that imported eggs have been established as the source.
