Legionnaires' disease: guidance, data and analysis

The symptoms, diagnosis, management, surveillance and epidemiology of Legionnaires' disease.

Legionnaires’ disease is a severe pneumonia caused by the Legionella bacterium. People become infected when they inhale aerosols from a contaminated source.

Early symptoms include muscle aches, tiredness, headaches, dry cough and fever. Sometimes diarrhoea occurs and confusion may develop. Legionnaires’ disease can cause long term health problems.

Diagnosis and management

Further guidance is available on:

The bacteriology reference department (BRD) offers a range of reference, confirmatory and referred tests for legionella.

Food, water and environmental laboratories carry out a range of specialist microbiology tests on food, water and environmental samples, and provide support required in the investigation of water-borne outbreaks such as Legionnaires’ disease.

Data submission

Legionnaires’ disease is a notifiable disease in England and Wales. Health professionals must inform local health protection teams of suspected cases. PHE collects data on notifiable diseases. This data helps healthcare professionals track identify clusters and prevent outbreaks whilst monitoring trends in disease occurrence over time.


Updates to this page

Published 1 August 2014
Last updated 14 January 2021 + show all updates
  1. Removed references to the European Surveillance Scheme.

  2. Added Monthly legionella report: December 2020.

  3. Added 'Legionnaires' disease: local summaries for England and Wales, 2016' to 'Epidemiology' section.

  4. Added 'Legionnaires' disease monthly surveillance reports: 2019' under 'epidemiology'.

  5. Added 'Legionnaires’ disease in residents of England and Wales: 2016'.

  6. Added Legionnaires' disease monthly surveillance reports: 2018.

  7. Added 2016 annual report.

  8. Added 'Legionnaires’ disease: risks of pre-heated birthing pools'.

  9. Added guidance for Legionnaires’ disease associated with travel to Dubai.

  10. Legionnaires' disease monthly surveillance reports 2017 uploaded.

  11. Link to investigating single cases of Legionnaires’ disease’ from CDPH, June 2002 has been removed.

  12. Legionnaires' disease: local summaries for England and Wales, 2015 uploaded.

  13. Investigation of Legionnaires disease: cases, clusters and outbreaks document uploaded.

  14. Added document for referring specimens for confirmation of Legionnaires’ disease.

  15. Legionnaires’ disease in England and Wales: 2015 report has been uploaded.

  16. Uploaded "Legionnaires’ disease: information on sampling of household water systems for householders".

  17. Added 2015 annual report.

  18. Added legionnaires' disease: investigation of household water systems guidance.

  19. Added 2016 monthly reports.

  20. Added regional summaries to Legionnaires' disease collection.

  21. Added Legionella: detection in healthcare premises.

  22. Added 2014 annual report.

  23. Added 'Legionnaires' disease in England and Wales: monthly data' to the collection.

  24. Added 2013 annual report.

  25. Added link to CDPH article on investigating single cases of legionnaires' disease.

  26. First published.