Prions. What are they? They‘re the smallest infectious particles one will ever meet. They’re what caused Great Britain to catch worldwide fame from the international community with an outbreak of “mad cow‘s disease” in the 1980’s. Cows seemingly going insane were somehow transmitting their symptoms of insanity to humans as well. This eventually sparked an international renewal of interest towards what had previously been an obscure infectious agent: prions (pronounced PREE-ons).

Prions are, simply put, the protein version of a viroid. Viroids are small strands of infectious RNA without a protein coat (in that sense differing from a typical virus) that target mostly plants. Viroids cause only rare one disease in humans: Hepatitis D.

Prions, on the other hand, are infectious agents that are the mutated form of the glycoprotein (proteins with carbohydrate receptors) PrP 27-30, which is typically found inside the brain. However, known by the common name of Creutzfeldt-Jakob Disease (referred to as CJD later in this article), prions occur when the normal PrP protein mutates from its normal form into an aggregated and mutated form. Although there are many speculative theories as to their origin and cause, the trigger for prions are still unknown. The mutated proteins (now referred to as prions) infect other normal PrP proteins and cause them to mutate as well simply through contact. While the act of mutating other proteins is unusual within itself, this exponential growth of aggregated prions within the brain leads to beta-amyloid plaque formation, which is one of the telltale signs for patients with Alzheimer’s as well. The growth of plaques lead to small holes forming within the brain, a condition known as spongiform encephalopathy, which leads to symptoms very similar to Alzheimer’s but with a quicker onslaught. Symptoms include loss of coordination, difficulty in speech and cognition, and general loss in brain function. Later and more severe neurodegenerative symptoms include violent mood changes, hallucinations, and dementia. There is no known cure as of this article‘s writing.

Thankfully, CJD is very rare; sporadic CJD occurs only in one out of a million people each year. However, spontaneous mutations are not the only way that CJD can form. Another infectious vector may lurk in one’s next barbeque.

The mad cow disease epidemic in Great Britain was spread through a horizontal transmission of contaminated beef; due to scant regulations of cow feed, the cows in Great Britain in the 1970‘s ended up cannibalizing the brains of their fellow cows. As mutated prions live in the brain, these cows contracted a form of CJD known as BSE (bovine spongiform encephalopathy), a form of CJD found within cows. Sterilizing contaminated beef had no effect, as prions are unable to be denatured through extreme heat, radiation, levels of pH, or virtually any other means. People eating contaminated beef contracted a version of CJD known as variant Creutzfeldt-Jakob Disease, essentially the same as normal CJD, but one that was able to spread with impunity. However, thanks to stringent security checks from the United States, no British beef was imported to the United States during that crisis, and there have only been four cases of vCJD within the United States to this date. Despite all the international fervor that BSE and vCJD caused, the quality of the cow feed remains an issue internationally even to this day. So next time you sit down for a juicy burger, simply reflect upon prions and think: is it really the zombies that want your brain?

<Edward Kim Oxford Academy 9th Grade>