Cases of deadly dirt disease melioidosis will increase as climate changes, expert warns
Melioidosis lives in soil year-round in the tropics but comes to the surface following heavy rain. (105.7 ABC Darwin: Emilia Terzon)
A senior tropical disease researcher is warning that cases of the potentially lethal soil-borne infectious disease melioidosis will increase due to climate change.
Melioidosis is caused by a soil-dwelling bacterium and can lead to pneumonia, blood poisoning and death.
Authorities in Townsville yesterday confirmed a person had died from the disease and several others were in intensive care following widespread flooding in the region.
Professor Bart Currie from the Menzies School of Health Research in Darwin said he expected the bacteria would increase in tropical regions due to the effects of climate change.
- Lung infections, from mild bronchitis to severe pneumonia (fever, headache, chest pains, appetite loss)
- Septicaemic pneumonia (infection in bloodstream and lungs) causing fever, headache, breathing difficulties, abdominal pain, joint pain and disorientation
- Localised infections can cause painful swelling, skin infection, ulceration and abscesses
Source: Queensland Health
Melioidosis lives beneath the soil’s surface year-round in the tropics but comes to the surface — and poses a greater risk to humans — following heavy rain.
Dr Currie said predictions showed increased temperatures and a greater number of severe weather events in the future would provide conditions for the bacteria to thrive.
A related increase in cloud cover would increase that effect, he told ABC Radio Darwin‘s Adam Steer.
“There’s an interesting link with sea surface temperature, not because it survives in salt water but because of the effects of sea surface temperature on the overlying clouds,” he said.
“It means that there will be more bacteria proliferating in the soil when there’s greater cloud cover, with less ultraviolet radiation to potentially kill the bacteria that come to the surface.”
Melioidosis is prevalent in soil across northern Australia and has caused clusters as far south as Central Australia following periods of heavy rain.
Rainfall during the current Top End wet season has so far been well below average, but Dr Currie warned the risk of contracting the disease was still present.
Melioidosis: The killer dirt disease
- Rare and potentially lethal bacteria present in the soil
- Comes to surface after heavy rains
- Contracted through drinking groundwater, getting dirt into cuts or breathed in when airborne
- Early symptoms include fever, cough, breathing difficulties
- Can lead to pneumonia, blood poisoning and death
- Risk factors include immune deficiencies, heavy drinking and liver problems
- Protective wear recommended when gardening in wet season
Health professionals have already dealt with 17 cases across the wet season.
Although that figure is a steep decline from the 60 during the previous season, Dr Currie said at-risk groups needed to remain vigilant.
“Darwin is absolutely the biggest hotspot for melioidosis,” he said.
“Darwin suburbs and the surrounding areas down to Humpty Doo are the areas where melioidosis occurs more per population than anywhere in the country.
“It’s a big issue for us each year.”
He said people with a predisposition to the illness were particularly those with diabetes, a hazardous alcohol intake and people taking some suppressive medications.
Melioidosis is contracted by drinking affected groundwater, when cuts come into contact with dirt and mud or by breathing in airborne particles in windy weather.
Risk groups are advised to avoid contact with environmental mud following severe weather and seek medical attention if they start to show symptoms, which include fever, cough and breathing difficulties.