The heavy rain and flooding that caused so much damage in north Queensland has now cleared, but in its wake stirs a deadly bacteria that has so far killed 12 people.
Melioidosis is a tropical infection caused by the bacteria Burkholderia pseudomallei.
While it’s often described as rare, melioidosis leads to thousands of deaths each year around the world, particularly in South-East Asia and India.
The bacterium lives in soil and mud and is drawn up to the surface during the heavy rains, like the ones that pummelled Ingham this month. (AAP: Adam Head)
It’s well known in Queensland and the Northern Territory, where the bacterium lives in soil and mud and is drawn up to the surface during the heavy rains of the wet season, or through digging.
Microbiologist Glen Ulett from Griffith University said flooding not only exposes the bacteria, but helps spread contaminated soil and water, increasing the risk it will find its way into a human body.
“Typically, through breaks in the skin, through wounds, through cuts or scratches or ingestion,” Professor Ulett said.
The bacteria can also find its way into the back of the throat through inhaling contaminated dust and soil, as soldiers discovered during the Vietnam War.
“Helicopters would disseminate the organism from dry soil, up into the wind, and Vietnam vets would inhale that and then get pneumonia in the lungs.”
‘Difficult to treat’ bacteria
What happens once it is ingested depends on how it enters the body, and the health of the person infected.
“If it’s entering through a cut in the skin, then we may just get skin changes. But if it’s inhaled then we might end up with pneumonia,” Professor Ulett said.
“The organism can enter into the bloodstream, and that would be the most severe form of infection if it becomes disseminated throughout the whole body.”
If the infection is not recognised and treated quickly using antibiotics it can lead to blood poisoning, or septicaemia, which is partly to blame for the melioidosis mortality rate of 20 to 50 per cent.
Infectious diseases specialist Peter Collignon said it’s particularly dangerous to people with pre-existing conditions such as diabetes and kidney failure, heavy drinkers, and those with an impaired immune system.
“It’s a difficult to treat bacteria. We do have antibiotics for it, but you need to be able to diagnose and get the right antibiotics in order to kill it,” he said.
“The very people that come out with the severe disease are also the most difficult to treat because their immune system doesn’t work as well.”
94 diagnosed across Queensland
Queensland government health data shows that 94 people have contracted melioidosis so far this year, more than four times the average rate of infection.
Of those cases, 53 have been reported in the Cairns and Hinterland area and 31 in Townsville.
Experts say many more people will have been infected, but either haven’t developed severe symptoms or any at all.
Professor Collignon said the early signs of infection — such as fever, feeling unwell, skin lesions, and problems breathing — are sometimes not attributed to melioidosis.
“If anybody looks particularly unwell in northern Australia with non-specific symptoms of any infection, you’ve got to think about melioidosis,”
he said.
“And so have blood tests done and chest X-rays done, particularly if you’re not feeling better in one or two days.”
Push for awareness
Queensland Premier David Crisafulli said his government would work to get the message out to the public and health professionals about the risks of melioidosis and its symptoms.
Friends and family members of those who are at elevated risk are also asked to keep an eye out for warning signs, and those who have returned from high-risk areas who are now feeling unwell should tell their health professional.
Melioidosis is also known as Nightcliff gardeners’ disease, named after the Darwin suburb where people digging in the soil were presenting with symptoms.
Infection risk expected to drop
Those who deal with soil are at particular risk of coming into contact with Burkholderia pseudomallei and are encouraged to cover up as much as possible.
“I know it’s unpleasant in hot weather, but wearing boots, wearing gloves for instance, all of that reduces the risk of getting it through your skin and multiplying through your skin before it travels to the rest of your body,” Professor Collignon said.
