Non-typhoidal Salmonella data 2014 to 2023
Updated 9 April 2025
Applies to England
© Crown copyright 2025
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Main points for 2023
The main points of the 2023 report are:
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the number of reported non-typhoidal Salmonella cases in England rose from 8,290 cases in 2022 to 8,874 cases in 2023, an increase of 7.0%
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in 2023 Salmonella Enteritidis was the most frequently reported serovar with laboratory reports increasing from 2,069 in 2022 to 2,710 in 2023; reports of Salmonella Typhimurium decreased from 1,772 to 1,471 and was the second most commonly reported serovar in 2023
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the region that reported the highest number of non-typhoidal Salmonella laboratory reports was London with 1,739 reports and the highest reporting rate of 19.4 reports per 100,000 population
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the age group with the highest number of laboratory reports was children below the age of 10 (2,063 non-typhoidal Salmonella cases)
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September was the peak month for non-typhoidal Salmonella reporting in 2023
Methods
All data presented in this report is correct as of 8 July 2024. This report covers all non-typhoidal Salmonella serovars in England. Data on typhoidal Salmonellae (S. Typhi and S. Paratyphi subtypes A/B/C) is available in the Enteric fever annual reports. The S. Typhimurium reported numbers include S. Typhimurium and its subtype Monophasic Typhimurium 1,4,[5],12:i:-. The S. Enteritidis reported numbers include S. Enteritidis only. The classification into typhoidal and non-typhoidal Salmonella serovars is consistent with established conventions in this area of research (1).
As data was extracted from the Second Generation Surveillance System (SGSS), a live laboratory reporting system, the data is subject to change and historical totals may differ slightly. The laboratory report date was used for all data analyses in this report.
Population data was sourced from the Office for National Statistics (ONS) for England. Mid-year population estimates for the relevant year were used to provide denominators for the calculation of rates. All rates are calculated as per 100,000 population.
Regional classification was based on place of residence of reported cases and classified using the Nomenclature of territorial units for statistics, level 1 (NUTS1) codes.
The deprivation level of an area (Index of Multiple Deprivation or IMD decile) was mapped to each case using patient home postcode.
When calculating the median of the previous 5 years, 2020 and 2021 were excluded due to the impacts of the COVID-19 pandemic, therefore the 5-year median was calculated from the same period in 2016 to 2019 and 2022.
COVID-19 pandemic
During 2020 and 2021 it is likely that the emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19), with subsequent non-pharmaceutical interventions (NPIs) implemented to control COVID-19 transmission affected notifications of Salmonella infections to national surveillance in several ways. These include, but are not limited to, changes which may have impacted ascertainment (for example changes in healthcare seeking behaviour, access to health care, availability or capacity of testing and so on) as well as changes which likely impacted incidence (for example limited foreign travel, closure of hospitality venues and attractions or behavioural changes around food consumption and so on) which will have also varied over time. Therefore, trends presented in this report should be interpreted with caution, and 2020 and 2021 data (the years a notable impact on Salmonella reporting to national surveillance was observed) is excluded when 5-year medians are calculated.
Salmonella laboratory data 2014 to 2023
1. Annual data 2014 to 2023
a. All non-typhoidal Salmonella
Table 1 and Figure 1 show the trend of non-typhoidal Salmonella laboratory reports in England from 2014 to 2023. The rate of non-typhoidal Salmonella laboratory reports per 100,000 population increased by 6.2% from 2022 to 2023
Table 1. Annual laboratory reports of non-typhoidal Salmonella in England from 2014 to 2023
| Year | Number of laboratory reports | Laboratory reports per 100,000 population |
|---|---|---|
| 2014 | 7,640 | 14.1 |
| 2015 | 8,185 | 14.9 |
| 2016 | 8,237 | 14.9 |
| 2017 | 8,670 | 15.6 |
| 2018 | 8,843 | 15.8 |
| 2019 | 8,402 | 14.9 |
| 2020 | 4,768 | 8.5 |
| 2021 | 5,001 | 8.8 |
| 2022 | 8,290 | 14.5 |
| 2023 | 8,874 | 15.4 |
Figure 1. Annual laboratory reports of non-typhoidal Salmonella in England from 2014 to 2023
b. Salmonella Enteritidis
Table 2 and Figure 2 show the trend of Salmonella Enteritidis laboratory reports in England from 2014 to 2023. The rate of Salmonella Enteritidis laboratory reports per 100,000 population increased by 31.0% from 2022 to 2023.
Table 2. Annual laboratory reports of Salmonella Enteritidis in England from 2014 to 2023
| Year | Number of laboratory reports | Laboratory reports per 100,000 population |
|---|---|---|
| 2014 | 2,367 | 4.4 |
| 2015 | 2,372 | 4.3 |
| 2016 | 2,219 | 4.0 |
| 2017 | 2,324 | 4.2 |
| 2018 | 2,589 | 4.6 |
| 2019 | 2,514 | 4.5 |
| 2020 | 1,290 | 2.3 |
| 2021 | 747 | 1.3 |
| 2022 | 2,069 | 3.6 |
| 2023 | 2,710 | 4.7 |
Figure 2. Annual laboratory reports of Salmonella Enteritidis in England from 2014 to 2023
c. Salmonella Typhimurium
Table 3 and Figure 3 show the trend of Salmonella Typhimurium laboratory reports in England from 2014 to 2023. The data includes Typhimurium and Monophasic Typhimurium 1,4,[5],12:i:- serotypes. The rate of Salmonella Typhimurium laboratory reports per 100,000 population decreased by 19.4% from 2022 to 2023.
Table 3. Annual laboratory reports of Salmonella Typhimurium in England from 2014 to 2023
| Year | Number of laboratory reports | Laboratory reports per 100,000 population |
|---|---|---|
| 2014 | 1,293 | 2.4 |
| 2015 | 1,627 | 3.0 |
| 2016 | 1,715 | 3.1 |
| 2017 | 1,965 | 3.5 |
| 2018 | 1,913 | 3.4 |
| 2019 | 1,569 | 2.8 |
| 2020 | 1,171 | 2.1 |
| 2021 | 1,199 | 2.1 |
| 2022 | 1,772 | 3.1 |
| 2023 | 1,471 | 2.5 |
Figure 3. Annual laboratory reports of Salmonella Typhimurium in England 2014 to 2023
2. Regional data
Table 4 displays the number of non-typhoidal Salmonella laboratory reports per region in 2023 as well as the rate per 100,000 population.
Compared to 2022, the rate of non-typhoidal Salmonella laboratory reports per 100,000 population increased during 2023 in all regions except the South East, where the rate dropped by 7.2% from 15.3 to 14.2 reports per 100,000 population. In 2023, London had the highest rate of laboratory reports at 19.4 per 100,000 population and the lowest rate was in the East Midlands, with 12.9 laboratory reports per 100,000 population. The largest increases in the rate of reporting, compared to 2022, were in the South West (up 21.1%) and North West (up 14.4%) regions, which rose from 14.7 to 17.8 and 12.5 to 14.3 respectively.
Table 4. Regional distribution of laboratory reports of non-typhoidal Salmonella in England 2023
| Region | Laboratory reports | Laboratory reports per 100,000 population |
|---|---|---|
| East Midlands | 646 | 12.9 |
| East of England | 928 | 14.3 |
| London | 1,739 | 19.4 |
| North East | 449 | 16.6 |
| North West | 1,085 | 14.3 |
| South East | 1,345 | 14.2 |
| South West | 1,035 | 17.8 |
| West Midlands | 830 | 13.6 |
| Yorkshire and the Humber | 817 | 14.6 |
3. Top 10 Salmonella serovars in 2023
Table 5 displays the number of laboratory reports for the top 10 most commonly reported Salmonella serovars in 2023. Compared to 2022, the top 3 reported Salmonella serovars remained the same in 2023 with an increase in reporting for S. Enteritidis by 32.6%, and decreases for S. Typhimurium (including Monophasic Typhimurium 1,4,[5],12:i-) and S. Infantis, by 15.0% and 17.1% respectively.
Table 5. List of top 10 non-typhoidal Salmonella serovars reported in England 2023
| Serovar | Laboratory reports |
|---|---|
| Enteritidis | 2,710 |
| Typhimurium (including Monophasic Typhimurium 1,4,[5],12:i:-) | 1,471 |
| Infantis | 257 |
| Saintpaul | 217 |
| Newport | 215 |
| Chester | 181 |
| Agona | 160 |
| Stanley | 156 |
| Java | 133 |
| Virchow | 124 |
4. Age and sex distribution in 2023
a. All non-typhoidal Salmonella
Figure 4 shows the age and sex distribution of non-typhoidal Salmonella laboratory reports in England during 2023, 8 laboratory reports were excluded where case age or sex was unknown. Overall, 52.6% of reported cases were female and the most affected age group was the 0 to 9 age category, accounting for 23.3% of total laboratory reports.
Figure 4. Age and sex distribution of laboratory reports of non-typhoidal Salmonella in England in 2023 (n = 8,866)
b. Salmonella Enteritidis
Figure 5 shows the age and sex distribution of Salmonella Enteritidis laboratory reports in England during 2023, there was no missing data for case age or sex. Overall, 51.2% of reported cases were female and the most affected age group was the 0 to 9 age category, accounting for 24.6% of total laboratory reports.
Figure 5. Age and sex distribution of laboratory reports of Salmonella Enteritidis in England in 2023 (n = 2,710)
c. Salmonella Typhimurium
Figure 6 shows the age and sex distribution of Salmonella Typhimurium laboratory reports in England during 2023, 1 laboratory report was excluded as case age or sex was unknown. Overall, 50.3% of reported cases were male and the most affected age group was the 0 to 9 age category, accounting for 28.7% of total laboratory reports.
Figure 6. Age and sex distribution of laboratory reports of Salmonella Typhimurium in England in 2023 (n= 1,470)
5. Index of Multiple Deprivation in 2023
Table 6 displays the number of non-typhoidal Salmonella cases resident in postcodes of each Index of Multiple Deprivation (IMD) decile. 102 laboratory reports were excluded where IMD decile could not be mapped. The median IMD decile of non-typhoidal Salmonella cases was 5 (inter quartile range: 3 to 8).
Table 6. Number of non-typhoidal Salmonella cases per IMD decile in England 2023
| IMD deciles | Total number of cases (%) |
|---|---|
| 1 (Most deprived) | 862 (9.8) |
| 2 | 958 (10.9) |
| 3 | 897 (10.2) |
| 4 | 899 (10.2) |
| 5 | 901 (10.3) |
| 6 | 864 (9.8) |
| 7 | 843 (9.6) |
| 8 | 880 (10.0) |
| 9 | 874 (10.0) |
| 10 (Least deprived) | 794 (9.1) |
| Total | 8,772 |
6. Seasonal variation in 2023
Figure 7 shows the seasonal trend of laboratory reporting for all non-typhoidal Salmonella, Salmonella Enteritidis and Salmonella Typhimurium in England during 2023 by month. In 2023, the number of laboratory reports per month of all non-typodial Salmonella broadly followed the same trend as the median of the previous 5 years, 2016 to 2019 and 2022 (excluding 2020 and 2021), peak reporting occurred in September.
Figure 7. Seasonality of laboratory reports of all non-typhoidal Salmonella, Salmonella Enteritidis and Salmonella Typhimurium in England in 2023
Foodborne outbreak data in 2023
Table 7. Foodborne outbreaks of non-typhoidal Salmonella reported in England in 2023 [Note 1]
| Agent | Total affected | Laboratory confirmed | Hospital admissions [Note 2] | Deaths [Note 2] | Setting | Food description |
|---|---|---|---|---|---|---|
| Salmonella Typhimurium | 2 | 2 | Unknown | 0 | Restaurant | Not Identified |
| Salmonella Braenderup | 4 | 4 | 0 | 0 | Restaurant | Leafy vegetables-coriander |
| Salmonella species | 10 | 5 | 1 | 0 | Restaurant | Red meat |
| Salmonella Infantis | 20 | 20 | 0 | Unknown | Multiple | Poultry meat |
| Salmonella Infantis | 71 | 64 | 5 | Unknown | Multiple | Poultry meat |
| Salmonella Saintpaul | 95 | 95 | 5 | Unknown | Multiple | Melons (2) |
| Salmonella Enteritidis | 255 | 255 | Unknown | Unknown | Multiple | Poultry meat (3) |
| Salmonella Enteritidis | 65 | 65 | 10 | Unknown | Restaurant | Eggs |
Note 1: Number of cases affected and number laboratory confirmed is for cases resident in England. Where the outbreak spanned more than one year, only the number of cases reported in 2023 is included in the table.
Note 2: Clinical outcome is not known for all cases and the data reported represents cases who have hospitalisations or deaths reported to national surveillance.
Conclusions
In 2023, the number of non-typhoidal Salmonella laboratory reports were almost as high as the highest rates seen prior to the COVID-19 pandemic (in 2017 to 2018) which appears to be driven by increases in Salmonella Enteritidis. Similar to 2022, the highest number of laboratory confirmed cases of non-typhoidal Salmonella in 2023 were in London. In 2023, September was the peak month for reported cases of non-typhoidal Salmonella, consistent with the 5-year median from 2016 to 2019 and 2022. However, this differs to 2022 when the peak reporting month was August. Representation of male to female cases was approximately 50% (where case gender was known), with 0 to 9 years being the most affected age group. Salmonella Enteritidis was the most commonly reported serovar, consistent with previous years prior to the COVID-19 pandemic.
Eight outbreaks of Salmonella were reported to national surveillance in 2023, comprising 522 cases of which 510 cases were laboratory confirmed. These outbreaks were associated with the consumption of multiple different food vehicles, including: poultry and red meat, eggs, coriander leaves and melons.
Data sources
This report was produced using data derived from 2 data sources. The first is the Second Generation Surveillance System (SGSS) run by UK Health Security Agency (UKHSA) (formerly Public Health England (PHE)). This is a live laboratory reporting system therefore numbers are subject to change. In 2014, PHE upgraded the laboratory reporting system so direct comparisons between data reported from the previous system (LabBase2) and the new system (SGSS) requires cautious interpretation.
The second data source is the Gastrointestinal Infections, Food Safety and One Health (GIFSOH) Division’s Electronic Foodborne and non-foodborne Outbreak Surveillance System (eFOSS), which is also a live laboratory reporting system and therefore numbers are subject to change.
The population data used for England and Wales was sourced from the ONS. Mid-year 2022 and 2023 estimates are available at the ONS population estimates.
Data caveats
This report was produced using laboratory data for England only, therefore the number of Salmonella laboratory reports published in previous reports which include data from other UK countries may differ to those included in this report. As data was extracted from SGSS, a live laboratory reporting system, the data is subject to change and historical totals may differ slightly.
Acknowledgements
We are grateful to:
- the NHS and private sector diagnostic laboratories, the microbiologists and local authorities, health protection and environmental health specialists who have contributed data and reports to national surveillance systems
- the epidemiologists and information officers who have worked on the national surveillance of intestinal infectious diseases
- colleagues in the Gastrointestinal Bacterial Reference Unit (GBRU) for providing the Reference Laboratory Services and laboratory surveillance functions and expertise
- UKHSA (formerly PHE) Information Management Department for maintenance and quality assurance of UKHSA national surveillance databases used for Gastrointestinal Infections (GI) pathogen surveillance at the national level
- UKHSA (formerly PHE) Local Public Health Laboratories and Food Water and Environmental Microbiology Services for providing a surveillance function for GI pathogens and testing of food and environmental samples routinely and during outbreak investigations
- all colleagues who have investigated and reported outbreaks to the eFOSS surveillance database
Prepared by Gastrointestinal Infections and Food Safety (One Health) Division, UKHSA.
For queries relating to this document, please contact salmonellasurv@ukhsa.gov.uk
References
1. Gal-Mor O, Boyle EC, Grassl GA. ‘Same species, different diseases: how and why typhoidal and non-typhoidal Salmonella enterica serovars differ’ Frontiers of Microbiology 2014: volume 5, page 391
2. McGeoch LJ, Hoban A, Sawyer C, Rabie H; Incident Team; Painset A, Browning L, Brown D, McCarthy C, Nelson A, Firme A, Pista Â, Moreno J, Martins JV, Silveira L, Machado J, Vasconcelos P, Olufon O, Inzoungou-Massanga C, Douglas A, McCormick J, Larkin L, Balasegaram S. ‘Salmonella Saintpaul outbreak associated with cantaloupe consumption, the UK and Portugal, September to November 2023’ Epidemiological Infections 2024: volume 152, article e78
3. European Centre for Disease Prevention and Control, European Food Safety Authority, 2023. ‘Three clusters of Salmonella Enteritidis ST11 infections linked to chicken meat and chicken meat products: 26 October 2023’