October is the start of Legionnaires’ season

It’s gardening season so it’s time to reach for the spade, the wheelbarrow, the gloves, and the face mask!

Canterbury Medical Officer of Health Dr Alistair Humphrey is warning gardeners to take care with bagged potting mix and compost to avoid life-threatening Legionnaire’s disease.

“Gardeners are at particularly high risk of catching Legionnaires’ disease as the bacteria thrives in bags of potting mix and compost,” says Dr Humphrey.

Dr Humphrey says 24 Cantabrians were diagnosed with Legionnaires’ disease last November – the highest monthly number ever recorded. It’s possible that up to fifteen cases may have occurred during Labour weekend.

62 Cantabrians were hospitalised with the disease last year. Thirteen of these patients spent extended periods of time in the Intensive Care Unit (ICU), including one patient who was in ICU for 42 days.

“The number of cases last spring was around three times more than average. We don’t know why the bacteria was particularly virulent then. One theory is that the warmer than usual spring led to potting mix and compost heating up in the bag more than usual – creating a perfectly warm and moist environment for the bacteria to thrive.” says Dr Humphrey.

Canterbury has the country’s highest incidence rates of Legionnaire’s disease, while New Zealand has the highest reported incidence of the disease in the world.

Five simple steps to avoid Legionnaire’s disease from potting mix or compost

It is important that gardeners follow these five simple steps to avoid catching Legionnaires’ disease from potting mix or compost:

  1. Open bags of compost or potting mix carefully – use scissors instead of ripping the bag
  2. Wear a well-fitting disposable face mask and gloves. Remember not to touch your mask while gardening.
  3. Dampen down the potting mix or compost with a sprinkle of water to reduce dust.
  4. Work with potting mix or compost in a well-ventilated area outside.
  5. Wash your hands thoroughly after handling potting mix or compost, or doing any gardening.

“Legionnaires’ is a very serious illness and these simple actions can be lifesaving” says Dr Humphrey.

Symptoms of Legionnaire’s disease to look out for

Symptoms of the disease may include:

  • dry coughing
  • high fever
  • chills
  • diarrhoea
  • shortness of breath
  • chest pains
  • headaches
  • excessive sweating
  • nausea
  • vomiting, and
  • abdominal pain.

The illness may be mild but can sometimes be fatal. It is more common in older people, particularly if they smoke, have poor immunity or a chronic illness. The incubation period for the disease is up to two weeks.

Anyone who gets these symptoms should see their general practice team immediately, and let them know they have been handling potting mix or compost recently.

Source: Canterbury DHB media release (4th October 2018).

Published on Thursday, October 4th, 2018, under News
Page last updated: 06/11/2018

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