MARK COLVIN: It's one of the hazards of living in Northern Australia but unlike malaria and dengue fever it's not very well known.
It's called melioidosis, an often fatal disease. It's caused by bacteria which are common in soils in tropical areas and which flourish during the wet season.
This wet season in the Northern Territory hasn't actually been very wet but today the Territory Government warned residents to be vigilant.
The past three wet seasons have seen higher numbers of melioidosis cases in the Territory and researchers are trying to work out why.
Sara Everingham reports from Darwin.
For some people who acquire melioidosis the symptoms are often similar to those of pneumonia and can come on suddenly or more slowly.
For Darwin resident Helen Bateman her symptoms became severe and she collapsed during a flight to Sydney.
HELEN BATEMAN: I became quite ill, lost my speech for a while, the capacity to walk, high fevers, lost 10 kilos in weight and it was just a struggle.
SARA EVERINGHAM: Vicki Krause from the Northern Territory Centre for Disease Control today helped issue a warning to Territorians about melioidosis, particularly to those with risk factors.
VICKI KRAUSE: Risk factors do include older age, being male, having underlying conditions such as diabetes as a very important risk factor, over use of alcohol, being on immunosuppressive drugs because of other diseases like cancer.
SARA EVERINGHAM: Darwin's Lord Mayor Katrina Fong Lim's family has had its own experience with the disease.
KATRINA FONG LIM: It's not very well known but my father, in fact the Lord Mayor of Darwin in the 80s, passed away due to complications due to melioidosis.
SARA EVERINGHAM: Researchers say the bacteria that causes melioidosis live below the soil's surface during the dry season but after heavy rainfall are found in surface water and mud and may become airborne.
Vicki Krause from the Northern Territory Centre for Disease Control.
VICKI KRAUSE: With the aerolisation of the bacteria causing melioidosis it's only in recent years that it's been actually recognised that this is probably a form of transmission.
Certainly saying that, we do know that back in the Vietnam War days it was felt that people acquired the disease, particularly soldiers who were under helicopters where the air was whipped up on the top of muddy surface water.
SARA EVERINGHAM: Researchers say the bacteria usually enter the body via cuts and sores in the skin.
The Northern Territory Health Minister Dave Tollner urged people to protect their skin when gardening this wet season.
DAVE TOLLNER: It's not to be seen in the Territory as being some sort of form of weakness by wearing gloves or covered shoes, because it is a very dangerous disease to pick up and the last thing we want is more cases.
SARA EVERINGHAM: In recent years in the territory melioidosis cases have been on the rise. The bacteria occur across northern Australia and in South East Asia.
And researchers believed it spread there from Australia some time during the last Ice Age.
Professor Bart Currie from the Menzies School of Health Research says Darwin has recently recorded the highest rates in the world.
BART CURRIE: What's happened is that there have basically been 252 cases in the last three years which is a massive increase because on average there are only in the 20 years before then 28 cases per year.
So, we had 96 cases in the last 12 months.
SARA EVERINGHAM: Nine of those cases last year were fatal. Severe wet seasons are partly to blame for the rise over recent years, but Professor Currie says last wet season was only just above average and there were more melioidosis cases than ever.
BART CURRIE: So we wonder whether first of all the preceding two years of intense rainfall may have set things up for a larger presence of the bacteria but we're also now looking at a number of other issues such as the massive amount of construction going on in the Darwin area with buildings of whole sites, whole suburbs being constructed.
SARA EVERINGHAM: Professor Currie says another factor is an increasing number of people in the Darwin area who have risk factors such as diabetes.
BART CURRIE: The thing that has increased most dramatically potentially from our work is the number of people who have what we call hazardous alcohol intake.
So we really talk about people who are going all the way to binge drinking, for instance. So, what we are most concerned about in that group is the level of alcohol in their blood at the time that they get exposed to the bacteria.
What the work shows is that the presence of high levels of alcohol in the blood literally paralyses the immune system.
SARA EVERINGHAM: Better awareness, detection and treatment mean the percentage of sufferers dying has reduced significantly.
But authorities want to stop people needing that treatment in the first place.
MARK COLVIN: Sara Everingham reporting.