A 64-year-old woman in New South Wales, Australia spent more than a year cycling through hospitalizations, inconclusive tests, and partial treatments before doctors found a living parasitic worm inside her brain — a species never previously documented in a human host.
Her symptoms began with three weeks of abdominal pain and diarrhea, accompanied by a dry cough and night sweats. A CT scan revealed opaque regions in her lungs consistent with inflamed or fluid-filled tissue, along with lesions on her liver and spleen. When physicians sampled fluid from her lungs, they found an elevated concentration of eosinophils — white blood cells the immune system deploys against infections and parasites. On that basis, doctors diagnosed her with eosinophilic pneumonia, a rare lung condition, and prescribed the corticosteroid prednisolone. Her symptoms partially eased.
Three weeks later she was back. The cough and fever had returned despite continued steroid treatment, and the organ lesions had not resolved. Cultures of tissue samples showed no bacterial or fungal infection. Blood work found no antibodies to common parasitic flatworms such as blood flukes or liver flukes, and stool samples came back negative as well. Doctors added ivermectin — a drug used against parasitic worms — partly because the woman had traveled to regions where such parasites are prevalent. Still, her respiratory symptoms persisted and worsened whenever she tried to lower her prednisolone dosage. Months passed without a clear diagnosis.
Roughly a year after her first admission, her condition changed in a new direction. She began experiencing episodes of forgetfulness and signs of depression. An MRI identified a lesion on the right frontal lobe of her brain. Surgeons performed an open biopsy to examine the site directly. Inside the lesion, they found what the case report describes as “a stringlike structure” — a living helminth, bright red in color, approximately 80 millimeters long and 1 millimeter in diameter.
The worm was later identified as Ophidascaris robertsi, an ascarid parasite typically found in Australian carpet pythons. It had never before been recorded infecting a human. The working theory is that the woman, who lived near a lake and regularly foraged native grasses, may have been exposed to python feces containing the parasite’s eggs. The parasite ordinarily uses small mammals as intermediate hosts. In this case, a human appeared to have taken that role, with larvae migrating through her abdominal organs, lungs, and ultimately her brain — a condition classified as neural larva migrans.
Surgeons removed the worm from her frontal lobe and found no additional parasites in the surrounding tissue. She was then treated with a two-day course of ivermectin combined with a four-week course of albendazole, a broad-spectrum anti-helminthic drug. Albendazole is absorbed by the central nervous system more readily than ivermectin, and the two drugs have been used in combination previously to address helminth infections with neurological involvement.
The case illustrates how parasitic infections can mimic other conditions across multiple organ systems for extended periods, particularly when the causative organism is one medicine has not previously encountered in humans. Standard diagnostic pathways — antibody panels, culture results, imaging — returned inconclusive findings at every turn. The diagnosis ultimately required direct surgical observation.
Photo by Alexis Plasencia on Unsplash
Source: Original reporting
