"Try this one..."
Leprosy gets a bad rap.
Sure, it's preferable to not have leprosy, but people who have it are neither
victims of their own sins - as was believed in the past - nor highly
contagious and doomed. DOOMED!
Leprosy is still a serious health concern in a few populations around the
world, but it's actually very treatable these days, especially if it's caught
early, and it has a low transmission rate. But the true facts about leprosy are
still fascinating - some morbidly so.
Here are five of them.
Armadillos are the only known carrier of leprosy
other than humans in the entirety of the animal kingdom.
The disease is caused by infection with the bacteria mycobacterium leprae and
it's been genetically proven that armadillos carry the exact same strain
that we do. But digging deeper than that
it's humanities fault that armadillos have leprosy to begin with!
This is surprising, because many zoonotic diseases - that is, diseases that can be
passed between humans and other animals - originated in other animals and only
started infecting us when we encroached on their natural habitats - like the flu or
Ebola but not so with leprosy.
Researchers think that the disease wasn't present at all in the western
hemisphere before Christopher Columbus spearheaded Europe's lasting contact
with the Americas in the late 1400s
and armadillos are only indigenous to the Western Hemisphere.
So it looks like they got it from us.
Susceptibility to infection with M. leprae is genetic and rare. Science hasn't
identified exactly what genes or more specifically what variants of genes
allow the bacteria to take hold
but at least a dozen have been implicated.
All of them are responsible for some aspect of immune system function on a
cellular level, meaning they affect how your immune system cells target and
respond to bodily invaders.
Most of our immune systems can identify and destroy leprosy bacteria without a problem.
One of the premier questions in genetics is how we can encourage specialized
cells to act like generalized stem cells.
Mycobacterium leprae do exactly that - they target your nervous system's
Schwann cells. These cells are part of the support system that insulates your
peripheral nerves - the ones that aren't in your brain and spine. Schwann cells
help those nerves grow, regenerate, and function.
Leprosy reprograms the Schwann cells. No one is entirely sure how, but M. leprae
bacteria take those cells and make them revert to a stem cell-esque state.
That is, they allow the cells to convert into other types of cells.
The converted cells then migrate through the body to join up with tissue of their new type.
The hijacked Schwann cells bring the M. leprae bacteria along with them
spreading the infection. If we could figure out how leprosy bacteria do that
we could potentially cure the disease and use the mechanism to create
treatments for degenerative diseases like Alzheimer's.
Written records of leprosy stretch back to 1500 BCE.
That's when it's first mentioned in the Egyptian Ebers papyrus
it's also mentioned in other ancient writings including asian area texts
dating back to 600 BCE.
But researchers have found even older evidence of the disease.
Skeletal remains found in modern day India indicate that leprosy was active
in at least 2000 BCE. That places it as one of the top ten oldest diseases
known today.
Medieval images of people with leprosy involved deformed features
sunken noses, shriveled hands and feet
that's not because those extremities just fell off. Without treatment, leprosy
bacteria caused damage to tissues throughout the body including lesions on
the skin, cysts on the bones, and destruction of the peripheral nerves.
As this damage continues, the body's resources for healing wounds becomes
seriously taxed. It doesn't help that with nerve damage you're not always
aware of minor injuries so you might not take steps to protect and heal hurts as
they happen.
Eventually, the body begins mining its own tissues for resources to fix the damage.
Cartilage becomes particularly valuable. The body steals it from everywhere, but
the effects are the most obvious in your extremities:
fingers, toes, and nose.
So, what diseases morbidly fascinate you? Get in touch and let us know and we
might make a video about it!
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more, check out 'How Leprosy Works' and thousands of other articles at
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