Sarah Says

Dr. Sarah Jarvis' health & wellness blog on Patient.co.uk

Legionnaires' disease in the news - no need for panic

Legionnaires’ disease can’t be passed from person to person.

Over the last week, we’ve seen news emerging of an apparently sudden outbreak of Legionnaires’ disease in Edinburgh - which has affected 40 people, 12 of whom are currently in intensive care – and may well have left many others feeling unsettled about the possible risks to their health.

Firstly, I’d like to stress the need for people who haven’t already been identified as being affected not to panic. Legionnaires’ disease can’t be passed from person to person and according to the news reports it appears as though the probable source of this outbreak – cooling towers local to this incident – has been identified.

We’re certainly not facing the 'rise of the superbug' scenario here. There have been about 350 cases of Legionnaires’ disease a year for the last few years and they usually happen in clusters like this one, with peak incidence between June and September.

How do you get Legionnaires’ disease?

Legionnaires' disease causes a serious lung infection which is caught by breathing in droplets of water which contain legionella bacteria. It’s an illness that can be fatal and the earlier it’s treated with antibiotics, the better the likely outcome.

The source of the bacteria in an outbreak is usually a man-made water distribution system where the bacteria have multiplied in great numbers. Warm storage tanks where the water stagnates are ideal for legionella bacteria to multiply.

Is the drinking water safe in areas affected by Legionnaires’ disease?

Yes, even in the areas affected by Legionnaires’ disease the drinking water will be quite safe, as the legionella bacteria only multiply in hot water at temperatures between 25° and 45°C - about 35°C seems to be the optimum temperature.

Legionnaires' disease can be caught from:

  • Piped water, especially hot water, in large buildings where long runs of pipe work can be a source of the bacteria.
  • Circulating water droplets in air-conditioning and cooling systems, cooling towers and evaporative condensers.
  • Whirlpool spas (jacuzzis), other warm-water baths and shower heads.
  • Decorative fountains.
  • Nebulisers and humidifiers (including some types of breathing equipment) if topped up with contaminated tap water.
  • Potting compost.
  • Plastics factories.

Risk factors in Legionnaires' disease

Anyone can develop Legionnaires' disease. However, you are more likely to develop this illness if you are already in poor health.

So do seek medical advice if you become unwell with high fever, cough, sweats and feeling generally unwell, and get urgent help if you develop shortness of breath or are coughing up blood.

The people who are at the highest risk are:

  • Over 50s.
  • Smokers.
  • People with long-term health conditions like chronic lung disease, diabetes or kidney problems.
  • Anyone with cancer or taking medicine which affects the immune system.
Posted by Dr Sarah Jarvis
Dr Sarah is unable to provide medical advice or respond directly to questions concerning your health. If you have health concerns we recommend contacting your GP.