Woman’s mystery illness turns out to be 3-inch snake parasite in her brain

From Ars Technica.com (Aug. 28, 2023):

A neurosurgeon in Australia pulled a wriggling 3-inch roundworm from the brain of a 64-year-old woman last year—which was quite the surprise to the woman’s team of doctors and infectious disease experts, who had spent over a year trying to identify the cause of her recurring and varied symptoms.

A close study of the extracted worm made clear why the diagnosis was so hard to pin down: the roundworm was one known to infect snakes—specifically carpet pythons endemic to the area where the woman lived—as well as the pythons’ mammalian prey. The woman is thought to be the first reported human to ever have an infection with this snake-adapted worm, and it is the first time the worm has been found burrowing through a mammalian brain.

When the woman’s illness began, “trying to identify the microscopic larvae, which had never previously been identified as causing human infection, was a bit like trying to find a needle in a haystack,” Karina Kennedy, a professor at the Australian National University (ANU) Medical School and Director of Clinical Microbiology at Canberra Hospital, said in a press release.

The case, reported in the latest issue of Emerging Infectious Diseases, began in January 2021. The woman went to a local hospital in southeastern New South Wales, Australia, with a three-week history of abdominal pain, diarrhea, dry cough, and night sweats. Her blood work indicated an infection of some kind, and scans showed signs of pneumonia in her lungs as well as lesions in her spleen and liver. But tests for known microorganisms and parasites came up negative, as did tests for cancers and autoimmune disease. She was diagnosed with an unexplained case of pneumonia and given a corticosteroid, prednisolone.

Three weeks later, she was admitted to another hospital for recurrent fever and persistent cough. Again, doctors found the lung, liver, and spleen injuries as well as signs of an infection. Her blood had high levels of eosinophils, white blood cells known to fight off parasitic infections. They treated her for the high eosinophil levels and, out of concern there was a false-negative for a human roundworm infection, treated her with the anti-parasitic drug ivermectin.

From mid-2021 to early 2022, the woman’s liver and lungs improved. With the addition of another drug to help keep her eosinophil counts down, she was able to lower the dose of prednisolone.  [read more]

Glad the doctors got the worm out in time.