MAD COW DISEASE: You’d wish it were fictional!

Before you start imaging screaming cows charging at anything and everything at free will, Creutzfeldt-Jakob Disease (CJD) or Bovine spongiform encephalopathy (BSE), shortly known as mad cow disease is, sympathetically, an incurable fatal disease affecting nervous tissue (brain and spinal cord). Bovine referring to cattle and spongiform referring to the nature of sponge like holes forming in the brain (encephalopathy). This progressive neurodegenerative disease peaked in 1993 and took a toll on hundreds of thousands of infected cattle along with 4.4 million others that were slaughtered to contain the disease. The first reported case of BSE was upon a post mortem examination of a cow in Sussex in September of 1985 and was confirmed in 1987.

Blame Game?

With increased aggression, nervousness, mood swings, ataxia and uncanny behavior, these list long symptoms show up after 4-5 years of infection. However, this onset of symptoms is shortly followed by death (weeks months). So who/what is the culprit?

Prions! Prions (pree-ons) are abnormal, misfolded versions of a protein commonly found in the cell surface membrane. Going on rogue sprees, prions self-replicate and have the ability to corrupt other proteins, which in turn assume the misfolded shape and carry on a cascade –collapsing more normal proteins; clumping; collecting and spreading!

What’s worse? –How BSE spread… (Disclaimer: Prepare to go Ewww!)

Cows, when slaughtered, are mainly consumed as beef while other parts are ground up into animal feed. This meant that healthy cows were fed with ground up meat and bones from sheep and other cows. If an infected cow was slaughtered –you can pretty much imagine the rest! (Other cows who fed on this feed became infected.) Another prion disease existing in sheep at the time (Scrapie) could have possibly been transmitted to cows via cattle feed.

Can Humans Become Infected?

Well… Yes and No! No, you can’t get mad cow disease as is but yes, you can get a human form of it: variant Creutzfeldt-Jakob disease (vCJD). This is fatal and may result from consuming contaminated nervous tissue of infected cattle. As there is no evidence for the existence of prions in muscle meat and dairy, you need not have the slightest worry –your steak is not at stake!

Although reported vCJD cases remain globally a few within recent decades (231), various reforms and policies have been implemented to counter its propagation. For instance, the federal government of the US bans high risk animals from entering the food supply and ensures that tissue from the central nervous system is removed from consumption. Other efforts also include bans on blood transfusions and donations if donors have been exposed to likely circumstances.

All in all, the efforts to curb this issue have undeniably been successful thus far with reportedly scarce
cases.

SAMATHI RAJAKARUNA

Links:

https://www.healthlinkbc.ca/health- topics/tu6533#:~:text=Mad%20cow%20disease%2C%20also%20called,)%2C%20which%20is%20also% 20fatal. https://www.webmd.com/brain/mad-cow-disease-basics https://www.youtube.com/watch?v=Pxojz6grwcU : What Happened to Mad Cow Disease?