Cryptosporidium data 2014 to 2023
Updated 30 May 2025
© Crown copyright 2025
This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gov.uk.
Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned.
This publication is available at https://www.gov.uk/government/publications/cryptosporidium-national-laboratory-data/cryptosporidium-data-2014-to-2023
Main points
The 2023 report shows that:
- the number of reported Cryptosporidium cases in England rose from 3,739 cases in 2022 to 6,837 cases in 2023, an increase of 3,098 cases (82.9%)
- the region with the highest number of Cryptosporidium laboratory reports was the North West with 1,384 reports, this was also the region with the highest reporting rate at 18.2 per 100,000 population
- overall, 55.4% of Cryptosporidium laboratory confirmed cases in England were female
- the age group with the highest number of laboratory reports was children aged 9 years or younger with 31.0% of total reports
- consistent with the previous 5-year median, in 2023 the number of Cryptosporidium reports peaked in the month of September
Methods
All data presented in this report is correct as of 21 May 2024. This report covers all Cryptosporidium species in England. National surveillance of cryptosporidiosis in England is coordinated by the Gastrointestinal Infections, Food Safety and One Health Division (GIFSOH) at the UK Health Security Agency (UKHSA) in collaboration with the Cryptosporidium Reference Unit at Public Health Wales which is the national reference laboratory. As a live laboratory reporting system was used for extraction, the data is subject to change and historical totals may differ slightly (see Data sources section for more information). 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 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 Cryptosporidium infections to national surveillance in a number of ways. These include, but are not limited to, changes which may have impacted ascertainment (for example healthcare seeking behaviour, access to health care, availability or capacity of testing) as well as changes which likely impacted incidence (for example limited foreign travel, closure of hospitality and attractions, such as petting farms, or behavioural changes around food consumption) which will have also varied over time. A large reduction in Cryptosporidium cases during the COVID-19 pandemic was observed (1). Therefore, trends presented for 2020 and 2021 in this report should be interpreted with caution, and 2020 and 2021 data is excluded from the calculation of 5-year medians. This approach is consistent with annual reports of other gastrointestinal pathogens.
The magnitude and duration of the impacts of the COVID-19 pandemic on the number of cases reported differed by gastrointestinal pathogen due to differences in severity, transmission routes and risk factors (2, 3). Therefore, the number of years impacted and consequentially excluded from the calculation of 5-year medians also differs by pathogen, for example 2020 and 2021 for Cryptosporidium but only 2020 for Campylobacter.
Cryptosporidium laboratory data 2014 to 2023
Annual data 2014 to 2023
Figure 1 and Table 1 show the trend of Cryptosporidium laboratory reports in England from 2014 to 2023. The rate of Cryptosporidium laboratory reports per 100,000 population increased by 83.1% from 6.5 in 2022 to 11.9 in 2023.
Figure 1. Annual laboratory reports of Cryptosporidium in England from 2014 to 2023
Table 1. Annual laboratory reports of Cryptosporidium in England from 2014 to 2023
| Year | Number of laboratory reports | Laboratory reports per 100,000 population |
|---|---|---|
| 2014 | 3,831 | 7.0 |
| 2015 | 4,981 | 9.1 |
| 2016 | 5,261 | 9.5 |
| 2017 | 4,000 | 7.2 |
| 2018 | 4,759 | 8.5 |
| 2019 | 4,333 | 7.7 |
| 2020 | 2,145 | 3.8 |
| 2021 | 2,510 | 4.4 |
| 2022 | 3,739 | 6.5 |
| 2023 | 6,837 | 11.9 |
Regional data in 2023
Table 2 displays the number of Cryptosporidium laboratory reports per region in 2023 as well as the rate per 100,000 population.
Compared to 2022, the rate of Cryptosporidium laboratory reports per 100,000 population increased during 2023 in all regions. In 2023, the North West of England had the highest rate of laboratory reports at 18.2 per 100,000 population and the lowest rate was in London, with 7.3 laboratory reports per 100,000 population. The largest increases in reporting rates compared to 2022 were in the South East (up 123.3%), North West (up 97.8%), and London (up 97.3%), which rose from 4.3 to 9.6, 9.2 to 18.2 and 3.7 to 7.3 respectively.
Table 2. Regional distribution of laboratory reports of Cryptosporidium in England in 2023
| Region | Laboratory reports | Laboratory reports per 100,000 population |
|---|---|---|
| East Midlands | 494 | 9.9 |
| East of England | 609 | 9.4 |
| London | 651 | 7.3 |
| North East | 409 | 15.1 |
| North West | 1,384 | 18.2 |
| South East | 914 | 9.6 |
| South West | 802 | 13.8 |
| West Midlands | 854 | 14.0 |
| Yorkshire and the Humber | 720 | 12.9 |
Age and sex distribution in 2023
Figure 2 shows the age and sex distribution of Cryptosporidium laboratory reports in England during 2023, 47 laboratory reports were excluded where the age or sex was unknown. Overall, 55.4% were female and children aged 9 or younger (0 to 4 and 5 to 9 age groups) were the most affected age group, accounting for 31.0% of total laboratory reports. A high number of cases reported were female aged 20 to 39 (n=1,691, 25.0%).
Figure 2. Age and sex distribution of laboratory reports of Cryptosporidium in England in 2023 (n = 6,790)
Index of Multiple Deprivation (IMD) in 2023
Table 3 displays the number of Cryptosporidium cases resident in postcodes of each Index of Multiple Deprivation (IMD) decile, valid postcodes were unavailable for 67 cases so could not be matched to IMD decile. The median IMD decile of Cryptosporidium cases was 6 (inter quartile range: 3 to 8).
Table 3. Number of Cryptosporidium cases per Index of Multiple Deprivation (IMD) decile in England 2023
| IMD deciles | Total number of cases (%) |
|---|---|
| 1 (Most deprived) | 601 (8.9) |
| 2 | 567 (8.4) |
| 3 | 632 (9.3) |
| 4 | 707 (10.4) |
| 5 | 680 (10.0) |
| 6 | 719 (10.6) |
| 7 | 724 (10.7) |
| 8 | 741 (10.9) |
| 9 | 730 (10.8) |
| 10 (Least deprived) | 669 (9.9) |
| Total | 6,770 |
Seasonal variation in 2023
Figure 3 shows the seasonal trend of laboratory reporting for Cryptosporidium in England during 2023 by month. In 2023, the number of laboratory reports per week broadly followed the same trend as the median of the previous 5 years, 2016 to 2019 and 2022 (excluding 2020 and 2021), but with an exaggerated peak in September compared to previous years, which was more than double the 5-year median. This increase was investigated in a published analytical epidemiological study (4).
Figure 3: Seasonality of laboratory reports of Cryptosporidium in England by month in 2023 with median number of reports by month in 2016 to 2019 and 2022 (excluding 2020 and 2021) (n = 6,837)
Outbreak data in 2023
In 2023, there were 21 Cryptosporidium outbreaks reported to national surveillance: 7 C. hominis, 8 C. parvum and 6 outbreaks where the species of Cryptosporidium was not reported (Table 4). Overall, the total number of people affected was 473 with 234 laboratory confirmed cases, of which 23 were hospitalised but there were no reported deaths. The larger outbreaks were reported at open, petting or commercial farm settings. C. parvum outbreaks were more commonly related to open or petting farm settings while C. hominis outbreaks were more common in swimming pool or other pool settings.
Table 4. Outbreaks of Cryptosporidium reported in England in 2023 [Note 1]
| Agent | Total affected | Laboratory confirmed | Hospital admissions [Note 2] | Deaths [Note 2] |
Setting |
|---|---|---|---|---|---|
| Cryptosporidium hominis | 22 | 14 | 0 | 0 | Other pool environment |
| Cryptosporidium species | 22 | 9 | 3 | 0 | Open/petting farm |
| Cryptosporidium species | 3 | 3 | 0 | 0 | Swimming pool |
| Cryptosporidium hominis | 2 | 2 | 0 | 0 | Other |
| Cryptosporidium hominis | 5 | 4 | 0 | 0 | Zoo/animal sanctuary |
| Cryptosporidium hominis | 4 | 4 | 0 | 0 | Swimming pool |
| Cryptosporidium parvum | 11 | 9 | 0 | 0 | Swimming pool |
| Cryptosporidium hominis | 2 | 2 | 0 | 0 | Commercial farm |
| Cryptosporidium species | 2 | 2 | 0 | 0 | Swimming pool |
| Cryptosporidium parvum | 264 | 77 | 14 | 0 | Open/petting farm |
| Cryptosporidium species | 3 | 1 | 0 | 0 | Commercial farm |
| Cryptosporidium species | 3 | 3 | 0 | 0 | Open/petting farm |
| Cryptosporidium parvum | 8 | 8 | 0 | 0 | Open/petting farm |
| Cryptosporidium hominis | 15 | 15 | 0 | 0 | Nursery |
| Cryptosporidium parvum | 12 | 10 | 0 | 0 | Open/petting farm |
| Cryptosporidium parvum | 42 | 26 | 0 | 0 | Commercial farm |
| Cryptosporidium species | 2 | 2 | 0 | 0 | Swimming pool |
| Cryptosporidium parvum | 5 | 4 | 2 | 0 | Open/petting farm |
| Cryptosporidium parvum | 36 | 29 | 4 | 0 | Open/petting farm |
| Cryptosporidium parvum | 3 | 3 | 0 | 0 | Swimming pool |
| Cryptosporidium hominis | 7 | 7 | 0 | 0 | Swimming pool |
Note 1: Number of cases affected and number laboratory confirmed for cases resident in England.
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 rate of Cryptosporidium laboratory reports per 100,000 population in England increased notably and was the highest rate reported in the 2014 to 2023 period covered by this current report. The highest rate of laboratory confirmed cases was in the North West. September was the peak month for reported cases, consistent with the 5-year median from 2016 to 2019 and 2022. Slightly more female cases (55.4%) were reported than male cases and children under the age of 9 years was the most affected age group (31.0%), similar to previously reported data.
Twenty-one outbreaks of Cryptosporidium were reported to national surveillance in 2023, comprising 473 cases of which 234 cases were laboratory confirmed. Most were linked to swimming or other pool environments or animal contact. Cryptosporidium species were not identified in 28.6% of outbreaks. C. hominis was identified in 7 outbreaks (33.3% of total outbreaks), 3 of which were in swimming pool or other pool environments. Six of the 8 C. parvum outbreaks were linked to commercial farms or open or petting farm settings and 2 were linked to swimming pools.
The 83.1% rise in the rate per 100,000 population from 2022 to 2023 was mostly driven by an increase in C. hominis cases reported in September and October (4). Reasons for the increase were multifactorial with travel and water-based leisure activities identified as potential exposures in a case-case study conducted in England and Wales (5). Findings suggested that the increase was initially driven by an importation of cases resulting from travel to popular Southern European travel destinations followed by localised UK transmission. Increased cases of cryptosporidiosis were also reported by other European countries in 2023, with epidemiological evidence suggestive of widespread transmission rather than a point-source outbreak (6). Potential explanations for this increased activity included increased travel post-pandemic and extreme climate conditions resulting in heavy rainfall and flooding across southern Europe during the summer of 2023 (7).
Data sources
This report was produced using data derived from 4 data sources.
the UKHSA Second Generation Surveillance System (SGSS) – this is a live laboratory reporting system, so 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) require cautious interpretation).
the Gastrointestinal Infections, Food Safety and One Health (GIFSOH) Division’s eFOSS (electronic foodborne and non-foodborne outbreak surveillance system) which is also a live laboratory reporting system and therefore numbers are subject to change.
The national Cryptosporidium Reference Unit at Public Health Wales which undertakes genotyping and supports outbreak investigations, therefore species and subtypes are derived from this data.
The population data used for England was sourced from the Office for National Statistics – mid-year 2014 to 2023 estimates are available at Population estimates – Office for National Statistics
Data caveats
This report was produced using laboratory data for England only, therefore the number of Cryptosporidium laboratory reports published in previous reports which include data from other UK countries may differ to those included in this report.
Acknowledgements
We are grateful to:
- the NHS and private sector diagnostic laboratories, 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 national Cryptosporidium Reference Unit (Public Health Wales) for providing the Reference Laboratory Services and laboratory surveillance functions and expertise
- UKHSA 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 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
Prepared by: Gastrointestinal Infections, Food Safety and One Health Division, UKHSA.
For queries relating to this document, contact: EEDD@ukhsa.gov.uk
References
1. Adamson JP, Chalmers RM, Thomas DR, Elwin K, Robinson G and Barrasa A. ‘Impact of the COVID-19 restrictions on the epidemiology of Cryptosporidium spp. in England and Wales, 2015–2021: a time series analysis’ Journal of Medical Microbiology 2023: volume 72, issue 6, page 001693
2. Love NK, Douglas A, Gharbia S, Hughes H, Morbey R, Oliver I, Smith GE, Elliot AJ. ‘Understanding the impact of the COVID-19 pandemic response on GI infection surveillance trends in England, January 2020-April 2022’ Epidemiology and Infection 2023: volume 151, e147
3. Love NK, Elliot AJ, Chalmers RM, Douglas A, Gharbia S, McCormick J, Hughes H, Morbey R, Oliver I, Vivancos R, Smith G. ‘Impact of the COVID-19 pandemic on gastrointestinal infection trends in England, February-July 2020’ British Medical Journal 2022: volume 12, issue 3, e050469
4. Williams SV, Matthews E, Inns T, Roberts C, Matizanadzo J, Cleary P, Elson R, Williams CJ, Jarratt R, Chalmers RM, Vivancos R. ‘Retrospective case-case study investigation of a significant increase in Cryptosporidium spp. in England and Wales, August to September 2023’ Eurosurveillance 2025: volume 30, issue 9, page 2400493
5. Peake L, Inns T, Jarvis C, King G, Rabie H, Henderson J, Wensley A, Jarratt R, Roberts C, Williams C, Orife O, Browning L, Neilson M, McCarthy C, Millar P, Love N, Elwin K, Robinson G, Mannes T, Young N, Chalmers R, Elson R, Vivancos R. ‘Preliminary investigation of a significant national Cryptosporidium exceedance in the United Kingdom, August 2023 and ongoing’ Eurosurveillance 2023: volume 28, issue 43, page 2300538
6. Schoeps A, Röbl K, Walter N, Neute A, Walter B, Freudenau I, Jurke A, Klier C, Heinmüller P, Saeed S and Metz J. ‘Increased number of cryptosporidiosis cases with travel history to Croatia might be related to swimming pools, Germany, 2023’ Eurosurveillance 2024: volume 29, issue 1, page 2300699
7. European Centre for Disease Prevention and Control (ECDC) ‘Communicable disease threats report, 22-28 October 2023, week 4’ 2023