Mad Cow Disease Mostly Infects Teenagers

Summary

Mad cow disease, or vCJD, is a rare but fatal prion disease that can be transmitted to humans through contaminated beef. The disease is caused by misfolded prion proteins that spread through the brain, causing severe neurological damage. Researchers discovered that teenagers are particularly vulnerable due to their higher number of Peyer’s patches in the intestines, which allow prions to enter the body more easily. Despite the global scare in the '80s and '90s, mad cow disease is now extremely rare thanks to improved monitoring and prevention measures in cattle.

Takeaways

• 😀 Mad cow disease (vCJD) is a fatal, prion-caused disease that can be transmitted through contaminated beef, causing neurological issues in humans.
• 😀 Prions are misfolded proteins that don't die because they're not alive, which makes prion diseases terrifying and hard to treat.
• 😀 The immune system cannot identify prions as foreign invaders, making it difficult for the body to fight off prion diseases.
• 😀 One misfolded prion can cause others to misfold as well, leading to brain cell death and worsening neurological symptoms.
• 😀 There are several types of Creutzfeldt-Jakob Disease (CJD), with variant CJD (vCJD) being linked to mad cow disease transmission from cows to humans.
• 😀 In the 1980s, cattle in the UK developed BSE (mad cow disease), and infected cows were turned into meat and bone meal, which was fed to other livestock, contributing to the spread of prions.
• 😀 The UK beef crisis in the 1990s led to human cases of vCJD, with symptoms taking over a decade to appear after exposure to prions.
• 😀 Despite widespread exposure to contaminated beef, only a few hundred humans developed vCJD, with most cases occurring in people under 30 years old.
• 😀 A 2016 study revealed that teenagers are more susceptible to prion diseases due to the increased number of Peyer's patches (immune cells) in their intestines, which allow prions to enter the body.
• 😀 As we age, the number of Peyer's patches decreases, explaining why younger individuals, especially those in their teens and early twenties, are more likely to develop vCJD after exposure.

Q & A

What is mad cow disease, and how is it transmitted to humans?

Mad cow disease, or variant Creutzfeldt-Jakob disease (vCJD), is a prion disease that can be transmitted to humans primarily through consuming infected beef. The prions, which are misfolded proteins, can corrupt normal proteins in the brain, causing severe neurological damage.

What are prions, and why are they dangerous?

Prions are misfolded proteins that can cause other proteins to misfold as well. They are dangerous because they aren’t alive, meaning the immune system can’t recognize and destroy them. Their ability to spread by misfolding other proteins makes them especially harmful, particularly in the brain.

What are the main types of Creutzfeldt-Jakob Disease (CJD)?

There are three main types of CJD: Sporadic, which occurs when a prion protein in the body misfolds spontaneously; Hereditary, caused by a genetic mutation; and Acquired, which is contracted through exposure to prions, such as through contaminated medical instruments or infected beef, leading to vCJD.

What makes prion diseases so hard to treat?

Prion diseases are difficult to treat because prions are resistant to heat, alcohol, and most sterilization processes. This makes it nearly impossible for the body’s immune system to fight them, and there are no current cures for prion diseases.

Why were teenagers more likely to develop mad cow disease than other age groups?

Teenagers were more likely to develop mad cow disease due to having more Peyer’s patches in their intestines, which contain M cells. These M cells can accidentally let prions into the body. Since teenagers have more Peyer’s patches than other age groups, they had a higher chance of being exposed to the prions.

What role do Peyer’s patches and M cells play in the transmission of prions?

Peyer’s patches are clusters of immune tissue in the gut, and M cells are part of the immune system that screens substances that pass through the intestines. M cells typically detect harmful invaders, but prions can slip through undetected, allowing them to enter the body and spread.

How did mad cow disease spread to humans in the UK during the 1980s?

Mad cow disease spread to humans in the 1980s when cattle infected with Bovine Spongiform Encephalopathy (BSE) were turned into animal feed, including meat and bone meal, which was fed to other cattle. Some of these infected cattle were later processed into beef products, leading to human exposure to prions.

What does it mean that prions are 'indestructible'?

Prions are considered 'indestructible' because they are resistant to many common methods of sterilization, such as heat and alcohol. They can even survive for years in the environment, which makes it difficult to completely eliminate them from contaminated areas.

Why did it take so long for humans to start showing symptoms of mad cow disease?

Mad cow disease has an incubation period of up to 10 years, meaning people could be infected with the prions for many years before showing symptoms. This long delay in symptoms made it difficult to immediately connect the disease to infected beef.

How many cases of vCJD have been reported in the last decade, and why is this number so low?

Fewer than 10 cases of vCJD have been reported globally in the last decade. This low number is largely due to effective prevention measures, including monitoring and controlling the food supply, and reducing the risk of prion contamination in cattle.