England and Wales recorded 463 confirmed Legionnaires’ disease cases in 2024, within 472 total legionellosis cases. Scotland recorded 57 Legionnaires’ cases in 2025. These distinct surveillance totals are explained below.
Legionnaires' disease is a severe, sometimes fatal pneumonia caused by Legionella bacteria breathed in as a fine water mist — from cooling towers, hot and cold water systems, spa pools and similar sources. This page gathers the current UK figures in one place: how many cases are diagnosed each year, how many people die, which organisms and exposure routes dominate, and what the enforcement picture looks like for the dutyholders who have to manage water systems. The figures are drawn from the UK Health Security Agency's (UKHSA) annual surveillance of legionellosis in residents of England and Wales, Public Health Scotland's (PHS) Scottish surveillance report, and the Health and Safety Executive's (HSE) legionella enforcement and guidance.
Key facts and figures
- 472 legionellosis cases were reported in England and Wales in 2024, including 463 Legionnaires’ disease cases, 8 non-pneumonic cases and 1 Pontiac fever case.
- 0.7 per 100,000 was the Legionnaires’ disease incidence in England and Wales in 2024; the denominator was 463 confirmed cases, not all legionellosis.
- 13 deaths were reported among England and Wales’s 463 confirmed Legionnaires’ cases in 2024: a case-fatality rate of 2.8% (95% CI 1.6–4.9%).
- 96.5% of confirmed Legionnaires’ disease cases in England and Wales in 2024 involved L. pneumophila: 447 of 463.
- 51.6% of England and Wales’s 463 Legionnaires’ cases in 2024 were community-associated, 43.8% associated with travel abroad and 4.5% healthcare-associated.
- 68.0% of the 463 Legionnaires’ disease cases in England and Wales in 2024 were male; 63.9% were aged 60 or over.
- 57 Legionnaires’ disease cases were recorded in Scotland in 2025, the same number as 2024; incidence was 10.3 per million in 2025.
- 2 deaths were reported among Scotland’s 57 Legionnaires’ disease cases in 2025, a case-fatality rate of 3.5%.
Checked on 15 October 2026. The latest England and Wales annual report covers 2024; Scotland’s latest covers 2025 and was published on 29 September 2026. Legionellosis totals include more than Legionnaires’ disease, and these national series must retain their own disease definition, year and geography.
How many cases of Legionnaires' disease are there in the UK each year?
UKHSA’s England and Wales report records 472 legionellosis cases in 2024: 463 confirmed Legionnaires’ disease cases, 8 non-pneumonic legionellosis cases and 1 Pontiac fever case. The Legionnaires’ incidence was 0.7 per 100,000 population (95% CI 0.7–0.8). Scotland’s newer report records 57 Legionnaires’ cases in 2025; adding different years and definitions would not produce a valid UK annual total.
Legionellosis is the umbrella term for Legionella infections, while Legionnaires’ disease is the pneumonic form. The England and Wales report’s detailed demographic, organism, exposure and mortality analyses use its 463 confirmed Legionnaires’ cases. Differences in surveillance, diagnosis and reporting also matter when comparing countries or periods.
Is Legionnaires' disease increasing or decreasing in the UK?
Confirmed Legionnaires’ disease cases in England and Wales fell from 609 in 2023 to 463 in 2024, a calculated reduction of 24.0%. The all-legionellosis total fell from 609 to 472. The table uses Legionnaires’ disease consistently, showing the pandemic-period low and subsequent rise and fall without mixing disease definitions.
Scotland’s 2025 total was unchanged at 57 cases, following the same count in 2024. PHS describes those two years as the highest counts excluding the 2012 outbreak, with no common sources or linked exposures identified. This differs from England and Wales’s fall in 2024 and should not be condensed into a single UK trend.
| Year (England and Wales) | Confirmed Legionnaires’ cases | Notable point |
|---|---|---|
| 2020 | 337 | Pandemic-period low |
| 2021 | 352 | Increase from 2020 |
| 2022 | 415 | Further increase |
| 2023 | 609 | Highest in the 2020–24 table |
| 2024 | 463 | 24.0% below 2023; incidence 0.7 per 100,000 |
All five rows use UKHSA’s 2024 report and its confirmed Legionnaires’ disease definition. Earlier publications can contain different historical counts because of revisions. The 472 headline legionellosis total must not be substituted for 463 in the final row or in the report’s detailed case percentages.
What is the death rate for Legionnaires' disease in the UK?
England and Wales reported 13 deaths among 463 confirmed Legionnaires’ disease cases in 2024, giving 2.8% (95% CI 1.6–4.9%). This is a case-fatality measure among reported cases, not a population mortality rate or an individual prognosis. Interpretation depends on diagnosis, reporting and follow-up as well as the characteristics of the cases.
Scotland reported two deaths among 57 cases in 2025, a case-fatality rate of 3.5%. This uses a different year from the England and Wales figure. Small counts make percentages unstable, so the comparison does not establish a difference in treatment quality or the risk for an individual patient.
Species comparisons also require caution. The England and Wales 2024 report identifies 13 Legionnaires’ cases involving L. longbeachae and 447 involving L. pneumophila. L. longbeachae can be associated with soil or compost exposure. Differences in observed case-fatality proportions across small historical species groups do not by themselves establish that one infection is intrinsically more lethal.
Which Legionella organisms and sources cause most cases?
L. pneumophila accounted for 447 of the 463 confirmed Legionnaires’ cases in England and Wales in 2024 (96.5%). The remaining 16 comprised 13 L. longbeachae cases and 3 cases whose species was not established. Water-system control remains important, but the total should not be described as 447 out of 472.
The principal exposure categories among those 463 cases were community, 239 (51.6%); travel abroad, 203 (43.8%); and healthcare-associated, 21 (4.5%). Community includes travel within the UK. These classifications identify relevant exposure histories and are not proof of the precise infection source in every case. Healthcare-associated cases also require appropriate water-system management and investigation.
Among the 463 confirmed Legionnaires’ disease cases, 315 (68.0%) were male and 296 (63.9%) were aged 60 or over. East Midlands had a reported rate of 1.3 per 100,000 (95% CI 1.0–1.6), compared with 0.7 overall. The descriptive figures alone do not determine whether exposure patterns, susceptibility or ascertainment explain a difference.
How many Legionnaires' cases are there in Scotland?
PHS recorded 57 Legionnaires’ disease cases in Scotland in 2025, with incidence of 10.3 per million. Of these, 39 (68.4%) were travel-associated and 18 (31.6%) community-acquired; 51 (89.5%) were aged 50 or older. Two deaths were reported. PHS classifies this release as official statistics in development.
The exceptional 2012 outbreak affects comparisons with earlier Scottish years. PHS’s 2025 report shows 103 cases across Scotland in 2012; that annual total must not be described as the number in the Edinburgh outbreak alone. National reports should be compared using their own definitions and reporting periods.
Who is legally responsible for controlling legionella in the workplace?
Employers and people controlling premises or water systems can have duties under the Health and Safety at Work etc. Act and COSHH. HSE’s L8 and HSG274 explain risk assessment, prevention or control, competent responsibility, monitoring and records. Where assessment shows a reasonably foreseeable risk that cannot be prevented, a written control scheme is needed. Low-risk systems can justify proportionate arrangements rather than a blanket programme for every building.
Legionella is a biological agent relevant to COSHH. Assessment should consider the system’s design, temperatures, stagnation and aerosol generation, followed by suitable control and review. General occupational lung-disease estimates are not a measure of legionella deaths, and the reported community and travel cases on this page should not all be described as workplace-acquired illness.
What happens when dutyholders get legionella control wrong?
Failure to assess and control a reasonably foreseeable legionella risk can lead to enforcement even when no illness has yet been established. HSE’s guidance requires dutyholders to understand their systems and assign competent responsibility, rather than relying only on a contractor’s visit or a past test result.
Where control is required, keep the written scheme effective: check the specified control parameters, maintain equipment, act on adverse results and review arrangements after relevant changes. A positive sample requires interpretation and action in the context of the system and assessment; a negative sample is not proof that management duties have been met.
Frequently asked questions
How many cases of Legionnaires' disease are there in the UK each year?
The latest annual reports checked on 15 October 2026 record 463 confirmed Legionnaires’ disease cases in England and Wales in 2024 and 57 in Scotland in 2025. England and Wales’s broader legionellosis total was 472. The different years and disease definitions should not be added into a UK annual total.
Is Legionnaires' disease increasing or decreasing in the UK?
England and Wales’s confirmed Legionnaires’ disease count fell from 609 in 2023 to 463 in 2024, a calculated 24.0% reduction. Scotland’s 2025 count remained at 57, the same as 2024. Different reporting periods and national patterns mean there is no single trend represented by those two comparisons.
What is the death rate for Legionnaires' disease in the UK?
Among reported confirmed Legionnaires’ disease cases, England and Wales recorded 13 deaths among 463 cases in 2024 (2.8%). Scotland reported two among 57 in 2025 (3.5%). These are different-year case-fatality measures, not population death rates or individual prognoses.
Who is legally responsible for controlling legionella in the workplace?
Employers and people controlling premises or systems may be dutyholders under health and safety law and COSHH. Assess the risk and appoint competent responsibility. Where a reasonably foreseeable risk cannot be prevented, implement an effective written control scheme, monitoring and records appropriate to the system, as explained in HSE L8 and HSG274.
What is the difference between legionellosis and Legionnaires' disease?
Legionellosis includes all Legionella infections; Legionnaires’ disease is the pneumonic form. England and Wales’s 2024 total of 472 comprised 463 confirmed Legionnaires’ cases, 8 non-pneumonic cases and 1 Pontiac fever case. Detailed percentages in that report mostly use the 463 Legionnaires’ cases.
Where does Legionella come from in a building?
Relevant sources include cooling towers, hot and cold water services and spa pools that allow multiplication and generate inhalable droplets. HSE identifies 20°C to 45°C as conditions favouring growth. L. pneumophila caused 447 of 463 confirmed Legionnaires’ cases in England and Wales in 2024; other species can involve different exposures.
Related guides
- COSHH Statistics UK: Hazardous Substances at Work
- Occupational Asthma Statistics UK
- Silica Dust Statistics UK: Exposure, Silicosis & Deaths
- The COSHH Regulations 2002 Explained
- How to Carry Out a COSHH Risk Assessment
Sources & references
- UKHSA: England and Wales 2024, disease-specific tables and denominators
- Public Health Scotland: surveillance report 2025, published September 2026
- HSE: legionella risk assessment and control duties
- HSE L8: Legionnaires’ disease approved code and guidance
- HSE HSG274: technical guidance
- UKHSA surveillance and investigation collection
Legionella is a COSHH biological agent — make sure the people managing your water systems understand the duty to assess, control and monitor before an inspector or an outbreak does.
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Mark writes about workplace health & safety, COSHH and accredited online training for COSHH Training, part of Online CPD Academy.