Legionnaires’ disease in Scotland in 2023

Public Health Scotland has published Scottish Legionnaires’ disease data for 2023, which shows an ongoing increase in cases and incidence.

Legionnaires’ disease is a severe form of pneumonia caused by legionella bacteria, which can be acquired if tiny droplets of water containing the bacteria are inhaled.

Symptoms can include a cough, difficulty breathing, chest pain, and a high temperature, often accompanied by vomiting and diarrhoea, and, in some cases, confusion.

The surveillance report shows that the case numbers in 2023 (54) exceeded those in 2022 (44).

Factors that may possibly explain the notification increases include changes in national testing policies; an ageing population with the presence of multiple coexisting conditions and changing weather patterns.   The increase in Legionnaires’ disease cases identified in Scotland is also reflected across Europe.

Legionella bacteria is most commonly found in water sources, in both natural and man-made environments such as air-conditioning units, jacuzzies and showers. A specific type of legionella can also be found potting compost and other composted materials that, on rare occasions, may result in infection.

Hazel Henderson, Consultant at Public Health Scotland, said:

“Legionella bacteria exposure most often occurs when a person breathes in tiny water droplets containing the bacteria. When travelling, running any showers and taps on hot for a few minutes and opening windows where possible can help minimise any risk of infection. Only a minority of people go on to develop symptoms, however, those who smoke or have underlying medical conditions are at higher risk.

“A less common type of legionella bacteria can be found in damp potting compost or mud. It’s advisable to ensure good hygiene in relation to gardening by wearing gloves, potting plants outdoors, and a mask if the workspace is dusty, particularly if indoors. It’s important to wash hands immediately afterwards, especially before eating or drinking.”

Read the annual report on Legionnaires' disease in Scotland for 2023 here.