First Human Case: Parasitic Worm Found in Woman's Brain After Eating Wild Greens

A case has been reported of a woman in her 60s who suffered prolonged lung infection, organ damage, and memory loss after eating wild vegetables picked near her home. The cause was confirmed to be a rare parasite never previously documented in human infections.

According to science publication Live Science, a 64-year-old woman living in New South Wales, Australia, visited a hospital after experiencing three weeks of abdominal pain and diarrhea. She also presented persistent dry cough and night sweats.

A CT scan of her lungs revealed areas of thickened, opaque lung tissue. Medical staff suspected fluid, pus, or white blood cells had accumulated in spaces that should contain air due to inflammation or infection. Damaged tissue was also observed in her liver and spleen.

When doctors extracted and analyzed fluid from her lungs, eosinophil levels—a type of white blood cell—were abnormally elevated. They diagnosed her with eosinophilic pneumonia, a rare condition, and prescribed daily doses of the steroid prednisolone. Symptoms improved somewhat, but the underlying cause remained unidentified.

The improvement was short-lived. Despite consistent prednisolone use, the patient returned three weeks later with cough and fever. Tests showed organ lesions remained unchanged.

Additional examinations failed to reveal a clear cause for her respiratory symptoms. Tissue cultures showed no signs of bacterial or fungal infection. Blood tests detected no parasite antibodies, and stool samples yielded similar results.

Doctors nonetheless considered parasitic infection because the patient had previously visited countries where such infections are common. Despite no clear evidence, they prescribed the antiparasitic drug ivermectin.

Respiratory symptoms persisted. Reducing prednisolone dosage worsened her condition. This pattern continued for months.

A year after her first hospital visit with no improvement, the patient developed depression and even experienced memory loss.

Doctors determined brain imaging was necessary. An MRI scan revealed a lesion in the right frontal lobe. A brain biopsy discovered a "thread-like structure" inside the lesion—a living parasite. It was bright red, approximately 80mm long and 1mm thick.

After removing the parasite from the frontal lobe, doctors examined surrounding tissue but found no additional parasites.

Following the biopsy, ivermectin was administered for two days. The broad-spectrum antiparasitic albendazole was given for four weeks to eliminate any parasites remaining in organs. Dexamethasone was also administered for 10 weeks to prevent further inflammation.

Six months post-surgery and three months after completing dexamethasone treatment, the patient's lung and liver lesions had disappeared and white blood cell counts returned to normal. Neuropsychiatric symptoms also improved.

This case attracted scientific attention because the parasite represented the first confirmed human infection of its kind. It was identified as a third-stage larva of Ophidascaris robertsi, a parasitic roundworm native to Australia. Adults parasitize carpet pythons, while larvae can infect other animals.

Carpet pythons commonly inhabited areas near the patient's lakeside home. Though she had no memory of direct contact with snakes, she reported frequently foraging for wild vegetables around her property.

Doctors concluded she likely became infected after touching or consuming plants contaminated with parasite eggs.

According to reports, these parasitic larvae can survive more than four years in laboratory mice. However, no human infection had been documented before this patient, nor had the parasite ever been found in a host's brain.