Legionnaires’ disease going unnoticed
Half of the country’s Legionnaires’ disease sufferers may be going undiagnosed, an industry leader says.
Little is known about the potentially deadly disease, which is often caught through gardening. However, the preliminary results of research by Professor David Murdoch suggests the difficulty in distinguishing it from other, more common, forms of pneumonia means the illness often goes unnoticed.
Jillian Wadsworth, 40, was rushed to Christchurch Hospital on November 9 and put in an induced coma the next day after going to her GP for the third time with flu-like symptoms. She is one of at least 12 Cantabrians struck by the disease in the past week, and one of two admitted to intensive care.
Murdoch said the disease was not as simple as a ‘‘Canterbury issue’’.
Up to twice as many people as first thought could be suffering from the complaint, with numbers in Christchurch remaining steady, while patient numbers in Hawke’s Bay and the Bay of Plenty were spiralling ‘‘much higher’’ after Murdoch’s research discovered the disease’s presence there.
Murdoch, who is exploring ways to produce compost and potting mix that lessen the risk of infection from the Legionella longbeachae bacteria strain, said he ‘‘wasn’t surprised’’ to see the number of cases skyrocket.
Even more sufferers might be going undiagnosed, he suggested, as many could not be tested to confirm they had the disease. ‘‘One of the ways we test is to have people cough up samples but some people can’t do that, so we can’t know for certain.’’
The spike was being blamed on a boost in the use of potting mix for spring gardening. Labour Weekend and the month of November were prime times for the disease to spread as warmer weather arrived and more people got out into their gardens, Murdoch said.
‘‘It shouldn’t put people off gardening but right now we’re just not sure of many of the details of [Legionnaires’ disease]. We’re not sure if some recipes are worse, if compost’s safer kept in storage, if home-made compost is affected. It’s surprising how little we really know.’’
New Zealand had one of the highest reported rates of Legionnaires in the world, with a disproportionate amount coming from Christchurch, but that was because there was more awareness and rigorous testing to reveal it, not more cases, Murdoch said.
‘‘We look for it harder in New Zealand, we’re a bit smarter about it. It looks a lot like pneumonia so lots of the world don’t test at all so they think they don’t have it.’’
Symptoms included muscle aches and headaches, tiredness, chills, shortness of breath, stomach pain, and diarrhoea. It could take days to be detected after the initial contact.
Canterbury medical officer of health Dr Alistair Humphrey said two more cases of Legionnaires had been notified since Wednesday.
In the past 12 months, 271 cases of Legionnaires’ disease were notified nationwide, with 49 of those in Canterbury, a district health board spokeswoman said.
Of those patients hospitalised with the condition, 30 per cent needed to be admitted to intensive care. In 2005, three people died from the disease in Canterbury.