The 8cm roundworm is a common parasite in kangaroos and carpet pythons – but not in humans. A parasitic roundworm typically found in snakes has been pulled “alive and wriggling” from a woman’s brain in a stomach-churning medical first, Australian doctors said Tuesday.

Baffled doctors performed an MRI scan on the 64-year-old Australian woman after she began suffering memory lapses, noticing an “atypical lesion” at the front of her brain.

It was an eight-centimetre (three-inch) roundworm, called Ophidascaris robertsi, which researchers said was a common parasite in kangaroos and carpet pythons – but not humans.

“This is the first-ever human case of Ophidascaris to be described in the world,” said infectious disease expert Sanjaya Senanayake.

“To our knowledge, this is also the first case to involve the brain of any mammalian species, human or otherwise.”The findings were published in the journal Emerging Infectious Diseases.