Melioidosis is the name given to any infection with the organism Burkholderia pseudomallei. The bacterium is common in the environment in tropical regions, where it is found in soil, mud, and water, especially in rice paddies.
Naturally-occurring infection is therefore primarily a disease of the tropics. Many animal species are susceptible including mammals, birds, and even reptiles. Most human cases do not arise from animal contact however, but from environmental exposure, and may be rapidly fatal. Occasional infections are diagnosed in UK residents following travel to endemic areas of the world.