A Live Parasitic Worm Removed from a Woman’s Brain

A neurosurgeon, Dr. Hari Priya Bandi, discovered a live worm measuring 8cm (approximately 3 inches) inside the brain of a 64-year-old Australian woman. The woman had been experiencing mysterious symptoms, prompting the investigation. The surprising aspect of the finding was that the parasite was still alive, making this occurrence possibly unprecedented.

Dr. Bandi recounted her reaction upon uncovering the worm, stating, “I was completely taken aback by its presence. It defied all logic, yet it exhibited unmistakable signs of life and motion.” Utilizing forceps, she managed to extract the worm, which continued to display robust movements, leaving the medical team feeling a bit queasy by the sight.

This particular roundworm, identified as Ophidascaris robertsi, continued to exhibit wriggling behavior even after its removal. A study detailing this extraordinary case was recently published in the journal Emerging Infectious Diseases. Remarkably, this worm was in its larval stage and belonged to a species native to Australia. Its ability to parasitize humans was previously undocumented.

Dr. Bandi collaborated with Dr. Sanjaya Senanayake, an infectious diseases physician at Canberra Hospital, to co-author the case study. Dr. Senanayake recalled being on duty at the hospital when the worm was discovered.

The woman’s symptoms initially began in January 2021, starting with abdominal pain and diarrhea, followed by fever, cough, and shortness of breath.

The patient was admitted to a local hospital in late January 2021 due to three weeks of persistent abdominal pain and diarrhea. This was followed by a continuous dry cough, fever, and night sweats.

Doctors suggested that these symptoms likely resulted from the migration of roundworm larvae from the intestines to other organs such as the liver and lungs. Despite performing respiratory samples and a lung biopsy, no parasites were identified in these tissue specimens.

“Trying to identify these microscopic larvae, previously unknown to cause human infection, was akin to searching for a needle in a haystack,” explained Karina Kennedy, another study author from Canberra Hospital.

By 2022, the patient began experiencing forgetfulness and depression, prompting an MRI scan. The scan revealed an unusual tissue injury within the right frontal lobe of the brain.

Dr. Senanayake explained that the brain biopsy was expected to uncover either a cancerous growth or an abscess. He added, “This patient had been treated… for what was a perplexing illness that we initially believed was an immunological condition, as we had never before encountered a parasite. Then, out of nowhere, a significant mass appeared in the frontal region of her brain.”

Dr. Bandi described the patient’s recovery after the successful removal of the worm. “She was tremendously relieved to finally have an explanation for the troubles that had been plaguing her for such an extended period.”

Six months after the removal of the worm, the patient’s neuropsychiatric symptoms had improved, although they persisted, as indicated in the journal article.

Following the surgery, the patient was discharged with antiparasitic medications and had not required further hospitalization. Dr. Senanayake emphasized that while the patient was faring reasonably well, close monitoring was necessary due to the novelty of the infection.

Typically found in carpet pythons, this worm’s larvae commonly infest small mammals and marsupials, which are then consumed by the pythons, thereby completing the parasite’s life cycle within the snake.

The researchers noted that this worm usually resides in a python’s esophagus and stomach and deposits its eggs in the host’s feces. Humans are considered accidental hosts for Ophidascaris robertsi larvae.

The patient, residing in southeastern New South Wales, likely contracted the roundworm while handling a type of native grass called Warrigal greens near a lake close to her home. This is where a python might have deposited the parasite through its feces.

In the recent case study, researchers indicated that the woman had used Warrigal greens for cooking and was likely infected by touching the grass or consuming the greens.

Roundworms are known for their resilience and adaptability to various environments. They can cause symptoms like stomach pain, vomiting, diarrhea, loss of appetite and weight, fever, and fatigue in humans.

Researchers cautioned that this case underscores the risks of diseases and infections transferring from animals to humans, especially as human habitats increasingly intersect with those of animals.

Dr. Senanayake pointed out, “Around 30 new infections have emerged worldwide in the past 30 years. Of these emerging infections, approximately 75% are zoonotic, implying transmission from the animal realm to the human realm. This category includes coronaviruses.”

Dr. Kennedy advised people who garden or forage for food to wash their hands after such activities to mitigate these risks.