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Poisoned with Parasites

Body Horrors
By Rebecca Kreston
Dec 28, 2014 5:48 AMNov 20, 2019 6:03 AM


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Tensions can run high when living with roommates. Quibbles over dishes, the rent and utilities, and even questionable hygiene practices can inflame tempers and sabotage relationships, leaving passive-aggressive notes and broken homes in their wake. There are many ways of managing a good home life within a shared household of semi-strangers, but we’ll save that for another time in another column. This is about a roommate dispute gone totally to the worms.

In 1970, four housemates living in Quebec were in a spat over the rent. Specifically, one housemate, a post-graduate in the department of parasitology at MacDonald College, was significantly late on his share of the monthly dues. Tensions ran high, and the quarrels continued. In what sounds like a particularly acrimonious argument, the delinquent housemate made a seemingly outlandish threat: he would poison them with the same organisms that he experimented upon in his laboratory, with the pig parasite Ascarissuum. His threat was quickly dismissed and the roommate was summarily evicted. 

It was only a week later when the four housemates ended up in a hospital after an elaborate dinner - yes, you’ve already figured it all out, haven’t you? - prepared by the delinquent room mate that the threat of poisoning by parasite was revisited. 

There’s something you have to know about the Ascaris roundworm. As with all parasitic worms, it takes a twisty, nomadic route through the body after it infects a human. It is transmitted by that most unsavory mode of infection, with the eggs reaching the mouth after exiting the body at the other end, the route of fecal-oral transmission. But the parasite is not content to be confined to the belly. After the larvae hatch from the egg, they fight their way out of the intestines, mosey their way to a blood vessel, and are delivered to the lungs. They burst out of the alveoli, crawl up the bronchi, ascend the trachea until reaching the back of the throat where they are swallowed and are delivered once again to the intestines. There the larvae will mature into adults, mate, and release their eggs in the feces, propelling their offspring into a new iteration of this magical journey of poop and procreation. 

From the Feb 27, 1970 issue of the Beaver County Times. Click to access the article.

In the four afflicted housemates, this porcine parasite began its circuitous voyage as described above, but instead of struggling skyward from the lungs to the throat before plunging back into the warm and welcoming environs of the gastrointestinal tract, these worms remained stuck in the lungs. The housemates came down with fever, cough, and malaise, but the most serious symptom was a severe shortness of breath, "respiratory distress" in medical parlance, which necessitated hospitalization.

The antibiotics that were first used as treatment failed to alleviate what was presumed to be community-associated pneumonia. Collection and analysis of their sputum did yield, however, the parasitic eggs that provided an end to the mystery. The exiled housemate's threat appeared to hold true: were the four men poisoned with food “maliciously seasoned” with ripe Ascaris eggs? (1) 

It was later estimated that the men had been infected with hundreds of thousands of eggs, far exceeding the usual dosage of a few eggs that can naturally occur in regions endemic with the parasite. Two men were so heavily dosed that they were in critical condition caused by acute respiratory failure from parasitic pneumonia. Thankfully, all poisoned men made a full recovery.

The miscreant roommate was charged with four counts of attempted murder. In court, he denied carrying out the threat and was eventually fully acquitted due to inconclusive and circumstantial evidence. The judge presiding over the case concluded that there existed a possibility that “the parasites might have gotten into the food by way of what the accused claimed was a recurring sewage backup into the kitchen sink of the house” (2). This plumbing defense was soundly denied by one of the poisoned roommates, however, and also raises the question of how a gentleman’s laboratory work with a tropical parasite could possibly be found in his kitchen sink in the midst of a Canadian winter.

As a pair of parasitologists writing about the esoteric subject of parasites in forensics remarked on the incident, “the fact that this is such an isolated case suggests that it is only when there is the rare coincidence of a parasitologist with a homicidal grudge that parasites are likely to be used for nefarious purposes” (3). For our sake, let us hope that parasitologists keep their study materials away from our bodies and, in an attempt to ensure that this case remains an isolated one, let us all make an effort to keep the parasitologists in our lives happy. 

More from Body Horrors 

Oy Vey!: Pig Tapeworm in the Orthodox Jewish Community

One Parasite’s Rise Amidst the Soviet Union’s Decline

The Fluke That Thwarted an Invasion


1) JA Phills et al (1972) Pulmonary Infiltrates, Asthma and Eosinophilia Due to Ascaris suum Infestation in Man. N Engl J Med.286: 965-970

2) L Levinson (June 10, 1971) Ex-Student is acquitted in parasite poison case. The Montreal Gazette. pp A1

3) A Gunn and SJ Pitt. (2012) Parasitology: An Integrated Approach. Hoboken, NJ: John Wiley & Sons

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