On Friday, a 28-year-old man from Sydney passed away from complications of a rat lungworm infection eight years after he contracted the microscopic parasite by eating a common garden slug on a dare.

According to the Australian outlet News.com, Sam Ballard had been living with significant brain damage sustained when the lungworm, a type of roundworm known as Angiostrongylus cantonensis, migrated from his digestive tract to his central nervous system.

A. cantonensis is found throughout Southeast Asia and the Pacific. As the name would suggest, the roundworm evolved to complete its lifecycle inside rats’ pulmonary arteries, yet through contact with food or water contaminated with rat feces, the organism can make its way into humans. Under normal circumstances, first-stage larvae hatch in rat lungs then make their way to the intestine, from which they are excreted back into the environment. Back in the soil, the larvae infect their intermediary hosts – snails and slugs. Following two months of maturation in the mollusks, mature third-stage larvae are ready to invade a new rodent, which they will get to do if one eats their unfortunate intermediary host.

But if they end up in a human intestine instead, third-stage larvae can wreak havoc trying to orient themselves. In cases where the A. cantonensis remain in the digestive tract, an inflammatory disease with symptoms similar to appendicitis may be triggered.

In other cases, the worm "can get lost, and it will go to the brain, and it'll stay there," Heather Stockdale Walden, an assistant professor in the Department of Infectious Diseases and Pathology at the University of Florida, told CNN. "When it gets to the brain, you can have eosinophilic meningitis." This condition involves inflammation of the membranes that surround the spinal cord and brain.  

Australian news show The Sunday Project, which first brought Ballard’s plight to public attention in 2017 (when the family’s healthcare funding had been slashed), reported that the young man began experiencing symptoms of eosinophilic meningitis just a few days after consuming the slug. The first sign was severe pain in his legs, which prompted him to go to the local hospital. He then fell into a coma for 420 days. During this period, and despite aggressive treatment, inflammation from the immune response to the worm(s) destroyed tissue in Ballard’s brain. He woke up partially paralyzed from the neck down and experienced difficulty communicating.

In the years since, he regained partial limb control through physical therapy, and continued to spend quality time with his friends and mother, who told News.com that “he understands” everything happening around him. Sadly, however, he continued to require 24/7 care until his death.

If you or a loved one experience the symptoms of meningitis – headaches, nausea, vomiting, and abnormal sensations in the arms and legs – seek medical attention right away. To avoid exposure to rat lungworm, don't consume raw or undercooked terrestrial mollusks and crabs, or freshwater shrimp, and thoroughly wash all raw fruits and vegetables.