Gardening Safely this Summer

As the weather warms up and more people head outdoors to garden during the spring and summer months, there is a corresponding risk of contracting two soil-borne diseases – Legionnaire’s Disease and Tetanus. While both diseases are rare, they are very serious – but preventable with some gardening precautions.

Legionnaire’s Disease

Legionnaire’s Disease (also known as Legionellosis) is a serious and sometimes fatal lung infection often associated with gardening. The Legionella bacteria that cause it are present everywhere in our environment, especially in the soil and in water (rivers, lakes and reservoirs).

The main sources of infection are from inhaling dust from compost, potting mix or soil or from breathing in fine aerosol droplets of water containing the bacteria. Water from air-conditioning units, spa pools or piped hot water is often found to be a bacterial source. Legionnaire’s disease can be caught in places like offices, hotels or hospitals if bacteria has gotten into the water supply.

Legionnaire’s disease can’t be passed on person-to-person, and you cannot be infected by drinking contaminated water.

Symptoms, diagnosis and treatment
Symptoms usually appear 2 to 10 days after exposure to the bacteria. The symptoms are very similar to the flu – fever, muscle aches, headache, loss of appetite, chest pain, breathlessness, tiredness, dry cough, nausea, vomiting, diarrhoea, mental confusion and disorientation.

A doctor who suspects someone has Legionnaire’s may take a mucus (phlegm) sample, blood test or order an x-ray to check the lungs.

Treatment for the disease is a course of antibiotics and these are best given early to stop the disease increasing in severity.

Who is more at risk of contracting Legionnaire’s?
Fortunately, most people have a natural immunity against the bacteria. However, people aged over 50, those who currently smoke or are ex-smokers, suffer from a chronic illness (especially lung disease) or have a weak immune system are more likely to contract Legionnaire’s.

There is no vaccination available to prevent Legionnaire’s but you can lower your risk of contracting it by:

• stopping smoking (you are five times more likely to get it if you smoke)
• wearing an N95 mask when working with potting mix, compost etc to give the best protection against dust
• using a low-pressure hose when watering the garden or compost
• monitoring spa pools – water testing and purification is necessary
• maintaining a hot water temperature over 60 degrees to kill the bacteria (have a mixing valve on taps to avoid hot water burns)
• maintaining and treating roof-collected tank water.

Simple prevention tips to stay safe when gardening:

• Be very careful to avoid generating dust when using garden products such as seed mix, compost, potting mix and soil.
• Wear a mask and gloves when opening these products.
• Open bags of garden products away from face – use scissors, rather than ripping open.
• Pot plants outside in a well-ventilated area.
• Dampen down products with water to stop dust spreading.
• Wash hands well after gardening and using garden products.

Tetanus (Lockjaw)

Another disease that can be contracted from contact with soil (as well as dust, horse and cow manure) is tetanus. Tetanus toxin released from tetanus bacteria is one of the most potent toxins known, with even a very small amount causing disease. Animals, including humans, carry the Clostridium tetani bacteria in the gut, which enter into faeces and eventually the soil. The bacteria then get into the body via a graze, cut, scratch, animal bite, puncture or road burn. Any wound has the potential for infection, not just deep or rusty cuts. Once in a wound, the bacteria release a toxic chemical that travels to the central nervous system, preventing transmission of nerve signals to muscles. As a result, the muscles are unable to relax. Left untreated the disease can cause heart failure, muscle and brain damage, airway obstruction, and death if respiratory muscles become paralysed.

Tetanus is not transmitted from person-to-person.

A vaccine is available to prevent tetanus
Infant vaccinations began in 1960 with an inactivated form of the toxin. On the current New Zealand Immunisation Schedule infants and children are given vaccinations at 6 weeks, 3 months, 5 months, then boosters at 4 years and 11 years. Boosters for adults are given at ages 45 and 65. A person will not have full protection against the disease until three or more doses of tetanus-containing vaccine have been given. Anyone born before 1960 is less likely to have had the primary course of three doses and may be at risk.

You may also need to get a tetanus booster shot within 48 hours of an injury if you are at high risk of contracting the disease or it is more than 5 years since your last booster.

The recognisable symptoms of tetanus
It can take up to a week (usually 3 to 10 days) for the first symptoms to appear after an injury – fever, sweating, mild spasms in jaw muscles, weakness, stiffness, muscle cramps, and difficulty chewing/swallowing. The disease progresses to muscle rigidity and painful spasms. When severe the classic lockjaw symptoms of facial grimacing and back arching appear.

There is no treatment for tetanus
Once the disease has developed there is no medicine available to treat it – this is why vaccination is so important. Patients will need supportive care in hospital as the disease progresses to help maintain their vital functions. Usually this means a stay in ICU for many weeks. Part of the hospital care is removal of infected wound tissue to decrease further toxin release.

Prevention tips for gardeners:

• Know your vaccination status.
• Keep broken skin covered when gardening.
• Clean any injuries straight away.

Taking a few simple precautions when gardening can reduce your exposure to these two harmful pathogens. Adults born before 1960 may need to check their vaccination status for tetanus to ensure they have been fully immunised.