This year marks 50 years of Legionnaires’ disease. In the summer of 1976, an outbreak in Philadelphia gave the disease its name. Fifty years on, the disease is well documented and the law is clear, and yet it still causes hundreds of UK cases a year. It still kills. The difference between a safe water system and a dangerous one comes down to how it is managed, and whether you can prove it.
The numbers
472 — cases of legionellosis in England and Wales in 2024, with 13 deaths
~1 in 35 — of people diagnosed with Legionnaires’ disease die from it
20–45°C — the temperature range where Legionella multiplies
5 — essentials every building with a water system needs
What’s inside the report
• Where it began — the 1976 Philadelphia outbreak
• The science and the law, in plain English
• Why the disease hasn’t gone away
• Where prevention still quietly fails
• How to protect your building — a five-point checklist
• The full 1976 → 2026 timeline
Download the free report below — it takes two minutes to read, and it could change how you look at every building you’re responsible for.
The figures in this report are drawn from published UK Health Security Agency data, and the duties described follow HSE guidance (ACoP L8 and HSG274).