Rise in Legionnaire’s disease numbers

Media Release

11 December 2008

Rise in Legionnaire’s disease numbers prompts reminder

The Ministry of Health is reminding gardening enthusiasts about the dangers of using potting mix without taking the necessary precautions, following a sharp rise in the number of cases last month.

20 cases of legionellosis (also known as Legionnaire’s disease) were notified last month, compared to seven last November. At this stage, five cases are confirmed, five are classified as probable and the remaining ten cases are still under investigation. Seven people were admitted to hospital as a result of the disease.

Five cases were from Canterbury, three from Counties Manukau with two cases each from Waitemata, Auckland, Waikato, Bay of Plenty, Capital and Coast and South Canterbury DHB regions.

Of the November cases where the exact bacteria strain has so far been found, the most common strain is Legionella longbeachae. This is the type commonly associated with potting mix or compost.

The Ministry's Director of Public Health, Dr Mark Jacobs, is urging all gardeners, amateur or professional to heed the warnings set out on bags of potting mix and when working around commercial compost stockpiles in order to minimise the risk of contracting this serious disease. The same care should be taken when handling “home made” compost, because legionella can thrive in compost bins.

“If you are working in the garden, please take care,” Dr Jacobs said.

Legionella longbeachae bacteria can be inhaled into the body when potting mix or other compost product is used, leading to a person developing Legionnaire's disease.

"The disease caused by the legionella bacteria is usually pneumonia but there maybe complications, particularly for those with existing respiratory illnesses, people with weakened immune systems, smokers, drinkers and the elderly," said Dr Jacobs.

“Of the 20 notifications in November, 12 cases were people aged over 60. Three people were in the 30-39 year age band with the remaining five aged 39 – 59.

While found naturally in the environment, legionella bacteria is most commonly contracted by inhaling contaminated dust or droplets. The disease is not spread from person to person.

Legionellosis causes lung infection or pneumonia. People should be aware of the symptoms of the disease, which include:

• Sudden high temperature and/or fever;
• Dry cough;
• Loss of appetite;
• Shortness of breath;
• Chills, muscle aches and headaches; and sometimes
• Stomach pain and diarrhoea.

"Anyone suffering from these symptoms should see their doctor.

People using potting mix can take a number of simple preventative measures:

• Always wear gloves and a mask;
• Take care when opening bags of potting mix and avoid inhaling dust;
• Moisten potting mix before use; and
• Washing hands thoroughly after using potting mix.

"Directions on how to reduce exposure to Legionella longbeachae bacteria are written on potting mix packaging. People should follow these instructions to reduce exposure," said Dr Jacobs.

The New Zealand Standard for Composts, Soil Conditioners and Mulches (NZS 4454:2005) launched on 16 December 2005 provides clear guidance to commercial producers of compost on how to process organic materials into compost in a safe and effective way. The Standard also includes bag labelling requirements, as well as promoting safe and healthy gardening practices.

Leaflets outlining health and safety while gardening are available from the Ministry of Health’s website http://www.healthed.govt.nz and Department of Labour’s website http://www.osh.govt.nz/order/catalogue/62.shtml or alternatively you can contact your nearest public health service.

ENDS

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