Rebecca Willers who runs the Shepreth Wildlife Park in Cambridgeshire was diagnosed in September with Diffuse Systemic Sclerosis - Representational Image AVM

A 37-year-old British zoo owner is slowly "turning to stone" after she was bitten by an insect while on a tiger trek in an Indonesian jungle in 2015.

Rebecca Willers was diagnosed in September with Diffuse Systemic Sclerosis, also called scleroderma, a deadly incurable condition. The disease has left Willers with hands that feel like "they are made of rock".

Willers, who runs the Shepreth Wildlife Park in Cambridgeshire, said she did not know how long she would live, Mail Online reported.

"Even brushing my teeth is difficult – I'm unable to grip anything at all. Animals are my life but now I sit in the zoo's office filling in paperwork.

"My doctor has warned me that the next three years will be the most aggressive."

Willers is currently waiting for her test results to know if the disease has affected her internal organs.

According to Willers's doctor, Professor Christopher Denton, her immune system "went into overdrive" after spending a lot of time in the jungle. Willers feels that an insect bite could have triggered the condition.

"I was genetically disposed to the disease and it just needs something to set it off."

After she returned back to the UK, she suffered a series of unrelated ailments until she was diagnosed with scleroderma, Mail Online stated.

"I began googling it and was terrified. Some people die within two years," she said.

According to Denton, "It's an extremely dangerous disease and it kills around half of all sufferers."

Willers's has also cancelled her pension and is trying to put her house on the market so that she can arrange money for her tests and treatment.

What is scleroderma?

Scleroderma is a rare disease whose cause is not yet known. It is not contagious, infectious, cancerous, malignant or hereditary.

Willers on her Facebook page wrote, "Some of my close friends are now aware that I was diagnosed with a rare autoimmune disease last month called Diffuse Systemic Sclerosis.

"The disease is a subtype of scleroderma, which affects my organs including heart, lungs, kidneys, GI tract, muscles and joints.

"I have been having lots of tests and still have a few more to do, however so far it looks like the disease is in its early stages, which is really amazing news. I start immunosuppressive therapy from today, and will be on this for life."

She added: "I'm embracing a very positive attitude as I'm acutely aware of how lucky I am to have been diagnosed so early. My symptoms began to manifest two years ago, however I'm still fortunate as many people are not lucky enough to have had such an early diagnosis.

"I would like to genuinely thank all my family and friends for their most incredible support.

"I have always been a very positive, upbeat person and there is no way this condition will change that about me, but I do know some people have found that a little hard to take – so I can only thank you for going through this process with me in the way that I have chosen."