Legionnaires' disease

Legionnaires' disease is a lung infection you can catch by inhaling droplets of water from things like air conditioning or hot tubs. It's uncommon but can be very serious.

How you get Legionnaires' disease

You can catch Legionnaires' disease if you breathe in tiny droplets of water containing bacteria that cause the infection.

It's usually caught in places like hotels, hospitals or offices where the bacteria have got into the water supply. It's very rare to catch it at home.

You can catch it from things like:

  • air conditioning systems
  • spa pools and hot tubs
  • showers, taps and toilets

You cannot usually get it from:

  • drinking water containing the bacteria
  • other people with the infection
  • places like ponds, lakes and rivers

When to get medical help

Urgent advice: Get advice from your GP now if

you have a bad cough and:

  • it does not go away
  • you cannot breathe properly
  • you have severe chest pain
  • you have a high temperature or feel hot and shivery
  • you feel like you have severe flu

These could be symptoms of Legionnaires' disease.

You should contact your GP and tell them where you have been in the past 10 days, such as if you stayed in a hotel, spa or hospital. Your GP will assess and advise you.

If you are unable to contact a GP and you are very unwell, you may need to go to your emergency department (ED).

Treatment for Legionnaires' disease

You may need to go into hospital if you're diagnosed with Legionnaires' disease.

Treatment in hospital may include:

  • antibiotics directly into a vein
  • oxygen through a face mask or tubes in your nose
  • a machine to help you breathe

When you start to get better you might be able to take antibiotic tablets at home. Antibiotic treatment usually lasts 1 to 3 weeks.

Most people make a full recovery, but it might take a few weeks to feel back to normal.


Content supplied by the NHS and adapted for Ireland by the HSE

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 18 May 2020
Next review due: 18 May 2023