Canberra Hospital infectious diseases physician Dr. Sanjaya Senanayake was called by a fellow  neurosurgeon on Monday who said: "Oh my god, you wouldn’t believe what I just found in this lady’s brain – and it's alive and wriggling."

The neurosurgeon, Dr. Hari Priya Bandi, pulled an 8cm-long parasitic roundworm from the 64-year-old woman's brain and asked Senanayake for advice on the next step. 

The patient was from south-eastern New South Wales and was first admitted to a local hospital in January 2021 after enduring abdominal pain and diarrhea, followed by a constant dry cough, fever, and night sweats over the course of three weeks.

When 2022 came along, her symptoms extended to forgetfulness and depression, which took her to Canberra Hospital, after which an MRI scan of her brain ensued, revealing unusual sightings requiring surgery.

Dr. Senanayake said: "But the neurosurgeon certainly didn't go in there thinking they would find a wriggling worm," adding: "Neurosurgeons regularly deal with infections in the brain, but this was a once-in-a-career finding. No one was expecting to find that."

"We just went for the textbooks, looking up all the different types of roundworm that could cause neurological invasion and disease," Senanayake noted, adding that the search was in vain leading them to resort to outside experts. 

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Senanayake continued: "Canberra is a small place, so we sent the worm, which was still alive, straight to the laboratory of a CSIRO scientist who is very experienced with parasites," adding: "He just looked at it and said, 'Oh my goodness, this is Ophidascaris robertsi'."

Blame it on the python

The Ophidascaris robertsi is commonly found in pythons, and this patient's case is considered the world's first case in which this parasite is found in a human.  

According to Senanayake, the woman was found to be residing by a lake near an area inhabited by carpet pythons, and although she was not in direct contact with the snakes, she would often collect grass from around the lake for cooking. 

Per a hypothesis by the doctors and scientists examining her case, a python may have shed the parasite through its feces into the grass that she collected and transferred the eggs to either food or kitchen utensils, or after eating the greens.

Senanayake explained that she was required to be treated for larvae that might have invaded other parts of her body like the liver. In turn, extreme caution was taken as some medications could trigger inflammation in the body even as the worm died off. 

Senanayake expressed: "You don’t want to be the first patient in the world with a roundworm found in pythons and we really take our hats off to her. She's been wonderful."

She is currently recovering well and is still being monitored, the doctor added, as researchers are figuring out if there was a pre-existing medical condition that caused the worm to find a home in her brain.

Animal-to-human transmission

According to the US Centers for Disease Control and Prevention (CDC), three-quarters of new or emerging infectious diseases in people originate from animals.

Senanayake believes that this case underlines how dangerous the passing from animals to humans is, saying that in the last 30 years, "about 30 new infections in the world" emerged. 

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"Of the emerging infections globally, about 75% are zoonotic, meaning there has been transmission from the animal world to the human world. This includes coronaviruses."

To ease worries, Senanayake claimed that this type of infection "does not transmit between people, so this patient's case won't cause a pandemic like COVID-19 or Ebola. However, the snake and parasite are found in other parts of the world, so it is likely that other cases will be recognized in coming years in other countries."