The disease is thought to be spread by a mosquito

According to the report, patients include Jan Smith, who contracted the ulcer on her left foot while training to climb a mountain Alaska.

“It just kept getting bigger and bigger,” she told a news website. “It was bright red [and] like a sock full of fluid.”

“I couldn’t sleep for the pain,” she said. “My husband said ‘I want to throw up because I see your bone’.”

Infectious diseases physician and medical researcher Professor Paul Johnson said the bug should not be ignored and more research needed to be done into the spread of the disease.

“We still don’t know a lot about where it’s coming from,” he said.

“One current theory is maybe it’s spreading in possums and somehow humans get infections indirectly.

“Maybe they are getting it from possums via mosquitoes. But maybe possums are just victims of it, like humans.”

“It starts as something strange and innocuous but it gradually gets bigger and looks like a small volcano on your skin.

“It gradually swells and hollows out and discharges.”

In rare cases the ulcer is known to have caused gangrene, the death and decomposition of body tissue.

Other cases have been recorded in Nigeria, Mali and other west African countries, with Australia as the only developed country to have an outbreak.

In three years the number of cases have doubled as 106 cases were recorded in 2015 compared to the 65 in 2013.

There have already been 45 cases recorded this year in Victoria alone.

WARNING: GRAPHIC VIDEO