Nelson Marlborough Health News and Notices

Legionella infection alert


Gardeners and spa pool owners are being warned to protect themselves against serious illness caused by Legionella bacteria.

Potting mix and inadequately treated spa pools are common sources of the respiratory illness Legionellosis.

Nelson Marlborough Health’s Public Health Service has received 11 notifications of Legionella infection this year, with 8 of these from 1 November. In 2015 only four cases were notified.

Dr Andrew Lindsay, Medical Officer of Health for Nelson Marlborough Health, says that Legionella infection can lead to Legionnaires disease – a serious illness that can cause pneumonia and death.

“Legionnaires is not passed from person to person but people can catch it by inhaling contaminated droplets of water in the air,” Dr Lindsay says.

“The Legionella bacteria lives in warm water, so people who have spa pools need to properly treat their water and maintain their pools. Maintenance of hot water cylinders and cooling towers is also very important.”

Another common source of Legionella is in the dust particles potentially inhaled when handling potting mix and compost.

“Six of the cases reported in 2016 appear to be linked to compost or potting mix. At this time of year, when people are getting into their gardens more they need to take care when handling these products,” Dr Lindsay says.

Dr Lindsay says that one the reasons for the increase in reported cases is the introduction of a successful, more sensitive laboratory test for the bacterium.

Steps to avoid Legionella infection when gardening:

  • dampen soil, potting mix or compost before using it to minimise the amount of dust 
  • wear gloves and a dust mask when handling soil, mulches, compost or potting mix
  • open bags of potting mix or compost slowly, in a well-ventilated area, and stand back as far as possible
  • open doors and windows while working in closed areas, eg glasshouses, potting sheds
  • use a gentle spray to water the garden and indoor plants
  • wash hands thoroughly after working with soil, potting mix or compost

People who own spa pools are reminded to maintain their pools and ensure they are properly treated to prevent the growth of Legionella bacteria.

People most at risk of becoming infected are usually over 50 years of age, smoke, or have chronic illnesses that suppress their immunity.

Symptoms of Legionella infection include:

  •  fever and chills
  •  flu-like symptoms and cough
  •  shortness of breath
  •  muscle aches, headaches and stomach pain
  •  vomiting and diarrhoea.

Anyone who develops these symptoms should seek medical attention immediately.

Regional breakdown of reported Legionella infections

Of the 11 cases reported between 1 January 2016 and 8 December 2016:

  •  6 were from the Marlborough region
  •  3 were from the Nelson region
  •  2 were from the Tasman region

Nine cases were for people in the 52–88 year-old age range.

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