"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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learn something here but to learn lots
more, check out 'How Leprosy Works' and
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