Sam Ballard swallowed the slug on a dare.

Ballard, a young rugby player from Sydney, was a “larrikin” — a “rough-and-tumble” free-spirit, his mother said. So when the creature crawled across a table at a party in 2010 and his buddies dared him to eat it, her son accepted the challenge, she said.

“Twenty-year-old boys, red wine, alcohol, sitting at some mate’s table — a slug goes onto the table, someone banters about a dare,” Katie Ballard told 7 News Sydney in an interview the following year.

“Boys will be boys,” she told the station.

The mate’s dare may have been innocent enough.

But after swallowing the slug, Ballard contracted a rat lungworm — a parasitic worm (Angiostrongylus cantonensis) that lives in rodents and can be passed onto snails and slugs, according to the Centers for Disease Control and Prevention. Those gastropods can then transmit the worm to humans.

In an unusual and tragic turn, the parasite infested Ballard’s brain — putting him into a coma for 420 days and leaving him paralyzed, according to News.com.au.

“It’s devastated, changed his life forever, changed my life forever,” his mother told 7 News Sydney in 2011. “It’s huge. The impact is huge.”

Ballard, whose mother said he once seemed “invincible,” is now a 28-year-old quadriplegic. He suffers from seizures, eats and breathes through tubes, and requires constant care, which the family is struggling to pay for, according to the Daily Telegraph.

The Australian newspaper reported that the family applied for a major disability package, worth about $383,000, under Australia’s National Disability Insurance Scheme in 2016.

But the government has cut Ballard’s allowance by more than 60 percent, according to the Daily Telegraph.

A National Disability Insurance Scheme spokeswoman told News Corp that it “has been working closely with the Ballard family” and that a resolution is “imminent.”

In 2011, Katie Ballard wrote on Facebook that her son was “still the same cheeeeeeeekkkyyy Sam” and that she believed he would talk and walk again.

Now, the family is struggling just to keep him alive.

The parasitic worm Angiostrongylus cantonensis lives in rodents’ lungs.

As the CDC explained in a video, the rodent — typically a rat — coughs up the worms and then swallows them, forcing them into the animal’s stomach. Eventually, the rat excretes the worms.

Snails or slugs can become infected by eating the rat’s feces, according to the CDC, and people can become infected by eating the snails or slugs.

According to the CDC:

People can get infected by eating raw or undercooked snails or slugs that are infected with this parasite. In some cultures, snails are commonly eaten. Some children, in particular, have gotten infected by swallowing snails/slugs “on a dare. ” People also can get infected by accident, by eating raw produce (such as lettuce) that contains a small snail or slug or part of one.

Certain animals such freshwater shrimp, crabs, or frogs, have been found to be infected with larvae of the parasite. It is possible that eating undercooked or raw animals that are infected could result in people becoming infected, though the evidence for this is not as clear as for eating infected snails and slugs. Of note, fish do not spread this parasite.

Cases have been reported in Hawaii, as well as some in the continental United States, according to the CDC. A New Orleans boy contracted the parasite in 1993 by eating a snail “on a dare,” according to the agency, but did not need treatment.

Australian health officials have called it “an extremely rare infection.”

The New South Wales Ministry of Health said in a fact sheet that most people who contract it do not experience any symptoms; when they do, the symptoms are usually temporary and mild, the health agency said.

According to the ministry:

Very rarely, rat lung worm causes an infection (infestation) of the brain called eosinophilic meningo-encephalitis. People with this condition may have headaches, a stiff neck, tingling or pain in the skin, fever, nausea, and vomiting. The time between eating the slug or snail and getting sick is usually 1-3 weeks.

Anyone with these symptoms should seek medical assessment although other infections (such as meningococcal disease or pneumococcal disease) are much more likely causes of meningitis in children.

Health officials warn people not to eat raw snails or slugs and to thoroughly wash fruits and vegetables and inspect them for the slimy creatures.

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