Bags of compost have been identified as the likely source of two legionella cases in Angus, a report has found.
Eight months on from a rare, nationwide outbreak of Legionnaires’ disease, Scottish health officials have finally determined that the majority of infections came from an overexposure to compost and incubating soil.
Health Protection Scotland has found that all seven patients had spent time in the garden or outdoors in the two weeks prior to their illness, and six had recently bought compost.
Some strains of legionella are found in soil and potting compost, but investigators found that the products used by the patients were bought at different times at different premises.
“Confirmed cases were severely unwell and all required treatment in intensive care units, including ventilation,” said a spokesman for the Health Protection Board, which carried out the investigation.
“The majority of cases were keen gardeners and had exposure to growing media, soils and water in the garden during their incubation period.”
In all, seven individuals in the Tayside and Lothian areas came down with the illness last autumn two of whom required treatment at Ninewells Hospital in Dundee.
The first case came to light on September 9, and was a 50 to 60-year-old female, who was admitted to intensive care with pneumonia. According to the report, she was a keen gardener.
Eight days later, a second patient with pneumonia was admitted to intensive care at Ninewells. The man, aged 70 to 80, also required ventilation.
He was not a keen gardener, but had taken ill after helping his wife in the garden.
According to investigators, six out of seven of those infected by the bacteria were growing potted plants outside of their homes. Four of the victims said they had not worn a mask while working with compost, and two said they drank or smoked while gardening making it easier for them to have ingested the legionella bacteria.
Investigators reckoned the majority of victims were exposed to the bacteria via shop-bought compost or soil enricher from both chain stores and independent retailers that were originally produced across England and Scotland.
But officials said no single site had been implicated in the investigation, and added that gardeners should note that the odds of being infected were highly unlikely.