When you think of deadly threats in Australia’s north, most people would think crocodiles or nasty jellyfish.
But it turns out there’s another lethal predator found right across the Top End, and it could be found right beneath your feet.
Authorities in the Northern Territory are this wet season tracking an unusual increase in melioidosis infections, otherwise known as Nightcliff Gardener’s Disease.
Three people have died from the bacteria in the territory since October.
Here’s a look at what melioidosis is, and what you can do to minimise the risk of getting infected.
What is melioidosis?
Melioidosis is an infection caused by a bacteria called Burkholderia pseudomallei, which is found across the tropics, and particularly in northern Australia.
That means residents in the northern most parts of Western Australia, the Northern Territory and Queensland are at risk.
If you live in Darwin, you might have heard it referred to as Nightcliff Gardener’s Disease, relating to the leafy suburb in the city’s north.
The bug is found in soil and is more prevalent after rainfall, with infections more common in the wetter months of the year.
What are the symptoms?
Dr Peter Markey from the NT government’s Centre for Disease Control says the infection can present itself anywhere on the body.
“It can be an infection just on the skin, it can be pneumonia or it can be anywhere in the body,” he said.
However, NT Health says the most common symptoms are a fever, a cough with mucus and difficulty breathing.
Non-healing skin sores can also be a sign of the disease.
Among those who know all too well about the fatal consequences of melioidosis is Katrina Fong Lim, whose father Alec Fong Lim died in the 1990s.
“In those days it was quite an unknown disease,” she says.
“It was basically flu-like symptoms, it was really a malaise. [He had] aching bones and some coughing and that kind of stuff, so it can quite easily be written off as the flu.”
How serious is it, and who is most at risk?
Thanks to modern medicine, deaths from melioidosis have been decreasing.
Without treatment, it can be fatal for up to 95 per cent of infections.
A Darwin-based study published in 2021 found that over a 30-year period, mortality dropped from 31 per cent of all cases to just six per cent.
Dr Markey says those most susceptible to catching melioidosis are those with pre-existing conditions, such as diabetes, chronic lung or kidney disease, or cancer.
People who are taking medication which suppresses their immune systems, or who frequently drink alcohol, are also at risk.
How can you catch it?
It’s very hard to catch melioidosis if it’s dry, but during northern Australia’s monsoonal wet season (December, January and February), conditions favour it multiplying and growing.
Being soil-borne, Burkholderia pseudomallei love wet, muddy conditions.
“In the wet seasons, the [bacteria] comes to the surface,” Dr Markey says.
While an open sore or cut in the skin coming into contact with mud or dirt is one way for the bacteria to infect someone, Dr Markey says there’s also the possibility you can breathe it in.
“It’s a good idea to stay inside as much as you can during the monsoon period where there’s a lot of rain and wind about,” he says.
“The wind and rains sort of sweep up the bugs, if you like, and aerosolise them, and you can just get melioidosis from breathing it in.”
How many cases have we been seeing?
Wetter weather means the bacteria are more abundant, and that’s led to a surge of cases in the Northern Territory.
The NT government’s disease control centre (CDC) has recorded 23 cases this season, including three deaths.
Dr Markey says that is well above what health authorities would expect this early into the wet season.
He says authorities would normally expect only eight cases of melioidosis to be diagnosed by early January.
NT Health data shows that in an average wet season, which runs from 1 October to 30 April, there are 32 cases of melioidosis with two deaths as a result.
Dr Markey suspects a surge in wet weather over the past two months has set up melioidosis with ideal weather.
“There is big fluctuation with our numbers usually, but this season does particularly seem to be a big one presumably because we’ve had this big monsoon early,” he says.