A live parasitic roundworm was discovered in a woman’s brain by Australian doctors, marking the first time the parasite is found in a person.

The 8cm-long Ophidascaris robertsi roundworm was discovered after brain surgery was performed on a 64-year-old woman by doctors at Canberra Hospital.

The “string-like structure” could have resided in her brain for up to two months, reported the BBC.

The parasite is a commonly found in carpet pythons, non-venomous snakes found in Australia. It had not been reported in humans until now.

It was suspected that the worm’s larvae had infected other organs in the woman’s body as well, reported Al Jazeera on Tuesday.

“This is the first-ever human case of Ophidascaris to be described in the world,” said Dr Sanjaya Senanayake, a leading infectious disease expert at the Australia National University and Canberra Hospital.

“To our knowledge, this is also the first case to involve the brain of any mammalian species, human or otherwise,” he added.

The case was documented in the September edition of the journal Emerging Infectious Diseases, said The Guardian.

Dr Senanayake told The Guardian that his neurosurgeon colleague Hari Priya Bandi said of the discovery: “Oh my god, you won’t believe what I just found in this lady’s brain – and it’s alive and wriggling.”

Dr Bandi, who was the one who pulled the parasite from the woman’s brain, called Dr Senanayake and other hospital colleagues for advice about the next steps, reported the Guardian.

The woman from south-eastern New South Wales was first admitted to a local hospital in late January 2021. This was after she suffered three weeks of abdominal pain and diarrhoea, followed by constant dry cough, fever and night sweats.

By 2022, depression and forgetfulness were added to her symptoms, prompting a referral to Canberra Hospital.

An MRI scan found that the woman’s brain had abnormalities and surgery was required, reported The Guardian.

“But the neurosurgeon certainly didn’t think... they would find a wriggling worm,” Dr Senanayake told The Guardian.

“Neurosurgeons regularly deal with infections in the brain, but this was a once-in-a-career finding. No one was expecting to find that.”

The woman lives near a lake area inhabited by carpet pythons, reported The Guardian.

Researchers believe that the woman was infected after foraging for edible shrubs near her house.

These were likely contaminated with parasitic larvae shed in snake faeces, reported AFP.