Two more people have died from melioidosis in Far North Queensland, bringing the death toll to four this year.
Melioidosis is a soil-borne disease linked to contaminated water and soil after heavy rain, and is currently spreading across Cairns, particularly in the southern corridor.
Cairns and Hinterland Health Service has recorded 41 cases since January 1, an unprecedented spike.
Health officials are investigating potential causes, including recent flooding, but say no single factor is to blame.
Melioidosis mainly affects those with weakened immune systems.
Symptoms include fever, cough, and skin infections and research is ongoing for a vaccine.
Early treatment with antibiotics is crucial, as the fatality rate is up to 10 per cent.
Residents have been urged to wear protective gear when handling soil or muddy water and avoid inhaling airborne bacteria.