In an unprecedented medical case that has left experts astounded, a 64-year-old Australian woman was found to have a live parasitic worm in her brain. The worm, identified as Ophidascaris robertsi, is a nematode whose primary host is usually a snake. This marks the first documented case of such an infection in humans, raising concerns about the increasing instances of “spillover infections” from animals to humans.
The woman, a resident of New South Wales, Australia, initially complained of abdominal pain and diarrhoea, which later escalated to night sweats, dry cough, and fever. Despite undergoing numerous tests for bacteria, fungi, and other parasites, doctors were unable to diagnose her condition. It wasn’t until she began experiencing forgetfulness and depression that her general practitioner recommended an MRI scan of her brain.
The scan revealed an unusual glow in her frontal lobe, leading to a biopsy that uncovered the live worm. “It was definitely one of those ‘wow’ moments,” said Dr Sanjaya Senanayake, an infectious disease physician at the Australian National University and the Canberra Hospital. “A worm in the brain!” But the discovery also brought relief, as it finally provided a pathway to treatment for the patient.
The worm typically resides in carpet pythons and is part of a life cycle involving small mammals like rats and possums. It is suspected that the woman may have ingested the worm’s eggs while collecting native warrigal greens near a lake inhabited by carpet pythons. The eggs likely hatched inside her body, leading to larvae that migrated to various organs, causing damage along the way.
While this is the first known case of O. robertsi infecting a human brain, it’s worth noting that other parasitic worms can also make their way into human tissues. For instance, Toxocara worms, which primarily infect cats and dogs, have been known to cause significant diseases in humans, particularly in children who come into contact with contaminated soil.
Dr Jill Weatherhead, an infectious disease doctor and parasitologist at Baylor College of Medicine in Houston, emphasised the importance of prevention. “This is why veterinarians encourage deworming,” she said. “Even though we are accidental hosts, the parasite can still cause significant disease in humans.”
The Australian woman is currently under medical supervision and has shown improvement after being treated with antiparasitic medications. Dr Senanayake warns that as human and animal habitats increasingly overlap, the risk of such unusual infections is likely to rise. “If you handle vegetation or wildlife, just make sure you wash your hands,” he advises. “And if you’re cooking and consuming vegetation, make sure you cook it well, just to reduce the chance of one of these unusual infections.”
This case serves as a stark reminder of the potential risks involved in the increasing encroachment of human activities into animal habitats. It also highlights the need for heightened vigilance in medical diagnostics, as the world grapples with the complexities of zoonotic diseases, which are infections transmitted from animals to humans.
Image credit: AUstralian National University