It is the time of the year in New Zealand when garden activity begins to ramp up.
Legionnaires' Disease is a serious public health concern because significant numbers of affected people require hospitalisation and there is a disturbing mortality rate.
Legionella longbeachae can be found in potting mix, compost heaps and composted animal manure.
Legionella pneumonophila can be found in watercourses and can also multiply in purpose-built water systems.
Last month a Christchurch man became unwell with cold and flu-like symptoms and four days later he was put into an induced coma in Christchurch Hospital's intensive care unit. After twelve days on life support he was transferred to a general ward and he then faced a lengthy recovery of at least several months in a hospital rehabilitation unit. What began as a cough and cold scenario accelerated into a life-threatening respiratory disease within hours.
Legionnaires' disease symptons include a dry cough, high fever, chills, diarrhea, shortness of breath, chest pains, headaches, excessive perspiration, nausea, vomiting and abdominal pain.
It is recommended to dampen any dry compost and potting mix (including bagged product) immediately after opening or using and avoid opening bags with one’s head right over the bag and avoid using any product in a confined space. Store opened bags in a cool environment and seal bag openings. Product which has been opened and is still around for more than twelve months can still be dangerous.
It is important to use P2 type facemasks which contain a filter and it is highly recommended to also wear protective gloves.
There are about thirty five species of Legionella and the most common is Legionella Pneumophila. It can be found in natural water supplies and in soil, but can also thrive in water supply systems such as hot water cylinders, industrial air conditioning units and spa pools. If conditions are favourable it can multiply rapidly, especially if water is stagnant. The ideal temperature range for Legionella to multiply is 25°- 45°C and it is unlikely to survive temperatures exceeding 60°C.
The risk of infection arises if one inhales water or soil particles which contains Legionella bacteria. Keeping water moving and if possible at temperatures either above 60°C or below 20°C is a prudent means of reducing risk at home but remember there is a risk of scalding with hot water at more than 60°C.
During 2017, sixty two Cantabrians were hospitalised with Legionnaires' Disease and thirteen required intensive care. One patient required intensive care for fourty two days.