Dr Humphrey says there were five simple actions gardeners should do to avoid getting Legionnaires':
• Open potting mix or compost carefully – use scissors instead of ripping the bag.
• Wear a well-fitting disposable face mask and gloves, and remember not to touch your mask when gardening.
• Reduce dust by dampening down potting mix or compost with a sprinkle of water.
• Work with potting mix or compost in a well-ventilated outdoor area.
• Thoroughly wash your hands after handling potting mix or compost.
Humphrey said several others had been admitted to hospital with the disease this year but did not require intensive care treatment.