Legionnaires’ cases in Scotland more than treble in three years, figures show

Cases of Legionnaires’ disease have more than trebled in Scotland over the past three years, new figures showed.

Cases of the lung infection fell to just 16 in 2021, but since then have risen, increasing to 44 in 2022, 53 the following year and 57 in 2024.

Public Health Scotland data showed that last year there were 10.4 cases of the condition per 1,000,000 people in Scotland – with this up from an incidence of 7.5 per 1,000,000 in 2023.

The health body said that the latest figures “continues an increasing trend in Legionnaires’ disease since 2021”.

It added that with the exception of the Legionnaires’ outbreak in Edinburgh in 2012, last year was “the highest number of cases and incidence observed in a year” where there were “no outbreaks, common sources, exposures or links identified”.

In a new report published on Tuesday, the health body made clear: “There were no outbreaks of Legionnaires’ disease detected in Scotland in 2024 and no known community outbreaks since 2012.”

Last year’s figures also showed that six people who had Legionnaires disease died, with Public Health Scotland saying this gave a case fatality rate of 10.5% – with this higher than the 9% case fatality rate for the disease that was reported in Europe in 2021.

More than half (56.1%) of Legionnaires cases in Scotland last year were linked to travel, with the number of cases acquired in the community falling from 32 in 2023 to 25 in 2023.

However Public Health Scotland noted that “the number of community-acquired cases is the second highest since 2017”.

According to the NHS, Legionnaires’ disease is contracted by inhaling droplets of water containing bacteria that cause the infection, with the condition “usually” caught in places such as hotels, hospitals or offices where the bacteria has got into the water supply.

It can cause coughing, a shortness of breath, chest pain, a high temperature and flu-like symptoms,  with those with the disease potentially needing treatment in hospital.

A Scottish Government spokesperson said: “It is not uncommon for there to be sporadic cases of Legionnaires’ with no identifiable cause.

“Public Health Scotland conducts enhanced surveillance of Legionnaires’ disease alongside the Scottish Microbiology Reference Laboratory.

“This allows us to identify and monitor trends, detect outbreaks, identify potential sources of infection, and inform measures to reduce the public health risk.”