Sandy’s Garden - Legionellosis

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Towards the end of the month of May, a story spread slowly across the media.

Unlike a murder, or the success of a celebrity or the latest scene in the Glasgow Rangers’ pantomime, this story didn’t hit the headlines on radio and television and in the printed news media all at once. Rather, the story was rolled out, progressing from a small item on a fairly specialist website to full-frontal exposure on BBC Newsnight Scotland. What I think was the original story appeared under the headline, “Gardeners urged to wash compost from hands.” Written by Peter Russell, the story was on WebMD UK Health News and began, “Gardeners are being advised to wash their hands after handling compost following a series of legionella cases in Scotland. One person has died and five others have become ill after being exposed to the Legionella longbeachae organism. Health Protection Scotland said three of the cases have been confirmed, two were probable and one was possible. Five of the cases involved keen gardeners, it said.”

Legionella longbeachae is one species of the family Legionellaceae. It was first isolated from a patient in Long Beach, California … as you may have surmised from its name … and is found predominantly in soil and potting compost. Human infection is particularly common in Australia, but cases have been documented in other countries including the USA, Japan, Greece and the United Kingdom. Here, legionellosis, the illness caused by the Legionella longbeachae bacteria seems, very strangely, to be almost-entirely confined to Scotland, although no-one seems to be wholly sure about how Legionella longbeachae spreads. The bacteria may be breathed in or it may be spread from hand to mouth, for it can remain active on a gardener’s hands for as long as an hour after compost has been handled.

The infection can be very serious, often leading to hospitalisation and sometimes … very occasionally, it must be said … death. It can be caught by anyone: but evidence, primarily from Australia and the United States, seems to suggest that older gardeners and those with a suppressed immune system are most vulnerable. Compost packaging in Australia carries a warning label; and the New South Wales state government recommends that people reduce exposure to potting mix dust by following the manufacturers’ warning present on potting mix labels, including: wetting down the potting mix to reduce the dust; wearing gloves and a mask when using potting mix; and washing hands after handling potting mix or soil, particularly before eating, drinking or smoking.

The symptoms of legionellosis include fever, coughing, breathlessness, chest pain and diarrhoea, which can, in the worst cases, be followed by pneumonia. It is worth stressing that the vast majority of gardeners who come into contact with the Legionella longbeachae bacteria do not become ill at all; so, in the words of Corporal Jones, “Don’t panic! Don’t panic!” But, given that there is a known … if very small … risk, it is also worth stressing that every gardener should follow the advice of Health Protection Scotland to wash their hands thoroughly after carrying out gardening tasks and before eating or smoking. It is surprising to learn that gardeners who have been handling soil which will certainly contain bird and animal droppings and may well have been fertilised with a product commonly referred to as ‘chicken s***’ apparently do not routinely wash their hands carefully before eating: but apparently some don’t; and if it takes a legionellosis scare to encourage better hygiene among such horticulturists, then that’s all for the good. But one can only reflect on the number of years during which cigarette packets have carried a health warning. And … need I say more?

Sandy Simpson, Polmont Horticultural Society