US Woman Thought She Was Jet Lagged, Later Doctors Found Parasitic Worms In Her Brain

A 30-year-old woman in New England experienced a rapid escalation of neurological symptoms. Starting with a burning sensation in her feet, the discomfort quickly spread up her legs, intensifying with even the slightest touch. Despite taking ibuprofen and visiting the emergency room, the cause remained unknown. Within five days, the burning had progressed up her torso and into her arms, leaving doctors perplexed, the Washington Post reported. 

A perplexing medical case recently detailed in the New England Journal of Medicine has shed light on a rare parasitic infection. In an 11-page case study published on February 12, doctors from Massachusetts General Hospital in Boston and the University of Washington chronicled how a woman sought treatment at three different hospitals as her symptoms worsened before finally being diagnosed with parasitic worms in her brain.

"This is just so unusual," said Robert Cowie, a research professor at the University of Hawaii and an expert on the parasite responsible for the infection.

Initially, the woman experienced an unexplained burning sensation in her skin and severe headaches. After a week, she made a second emergency room visit, where tests showed an elevated immune cell count, but her overall examination appeared normal. She was sent home with instructions to follow up with her primary care physician.

However, the next morning, her condition worsened- she became confused, began packing for a nonexistent vacation, and could not be dissuaded by a family member. Concerned, her partner rushed her to Massachusetts General Hospital.

Doctors learned that she had recently returned from a three-week trip to Thailand, Japan, and Hawaii. During her travels, she had eaten street food in Bangkok (though none of it was uncooked), raw sushi in Tokyo, and both salad and sushi in Hawaii, where she also swam in the ocean multiple times.

A spinal tap revealed abnormally high levels of eosinophils-white blood cells that combat parasites-prompting doctors to conclude that she had been infected with Angiostrongylus cantonensis, commonly known as rat lungworm. While adult worms reside in rodents, their larvae are excreted in faeces and can be transmitted to humans through contaminated snails or slugs. In humans, the larvae do not mature into adults but can survive long enough to cause serious neurological damage.

Cowie, who was not involved in the woman's case, criticized the delayed diagnosis, stating that doctors "took forever" to identify the cause of her illness. He has long warned about widespread ignorance among medical professionals regarding rat lungworm disease, also known as eosinophilic meningitis. A lack of awareness, he noted, could put patients at risk if they do not receive anti-parasitic medication in time to prevent severe or even fatal complications.

According to the Centers for Disease Control and Prevention (CDC), rat lungworm symptoms range from mild or nonexistent to severe headaches, neck stiffness, tingling sensations, low-grade fever, nausea, and vomiting. In extreme cases, the pain can be excruciating. When Hawaii saw a surge in cases in 2017, one infected woman described the agony as worse than childbirth. "That was like eating ice cream compared to this," she told KHON at the time. "It felt like someone stuck an ice pick into my collarbone, my chest, and the back of my neck."