Why is meningitis so dangerous? - Melvin Sanicas

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In 1987, thousands of people gathered in Saudi Arabia for the annual Hajj pilgrimage. But what started out as a celebration led to a worldwide health crisis: more than 2,000 cases of meningitis broke out, spreading across Saudi Arabia and the rest of the world. How did it spread so quickly and what makes meningitis so dangerous? Melvin Sanicas examines how the disease affects our bodies.

Lesson by Melvin Sanicas, directed by CUB Animation Studio.

In 1987, tens of thousands of people

gathered in Saudi Arabia
for the annual Hajj pilgrimage.

But what started out as a celebration
led to a health crisis:

just a few days after the pilgrimage,

more than 2,000 cases
of meningitis broke out

spreading across Saudi Arabia
and the rest of the world.

The outbreak was so fierce

that it was believed to have sparked a
wave of deadly meningitis epidemics

that ultimately infected tens of
thousands of people worldwide.

Meningitis is the inflammation
of the meninges,

three tissue layers responsible for
protecting the brain and spinal cord.

What makes meningitis so dangerous
compared to other diseases

is the sheer speed with which
it invades a person’s body.

In the worst cases, it causes death
within a day.

Fortunately, that’s rare for patients
who receive early medical treatment.

The disease primarily
comes in three forms:

fungal, viral, and bacterial--
the last being the most deadly by far,

and what we’ll focus on.

People usually contract bacterial
meningitis by breathing in

tiny particles of mucus and
saliva that spray into the air

when an infected person
sneezes or coughs.

It can also be transmitted
through kissing,

or sharing cigarettes,
toothbrushes or utensils.

Some people can be infected
and carry the disease

without showing symptoms
or getting sick,

which helps the disease
spread quickly to others.

Once the bacteria enter
the nose, mouth, and throat,

they cross the surrounding
membranes and enter the bloodstream.

From there, bacteria have
rapid access to the body’s tissues

--including a membrane
called the blood-brain barrier.

This is made of a tight mesh of cells which
separate blood vessels from the brain,

and block everything except
for a specific set of particles,

including water molecules and some gases.

But in ways that scientists are
still trying to understand,

meningitis bacteria can trick
the barrier into letting them through.

Inside the brain, the bacteria swiftly
infect the meninges.

This triggers inflammation as the body’s
immune response kicks into overdrive,

bringing on fever
and intense headaches.

As swelling in the meninges worsens,
the neck begins to stiffen.

Swelling in the brain disrupts its
normal function--

causing symptoms like hearing loss
and extreme light sensitivity.

As pressure increases in the cranium,
it may also make the person confused--

one of the hallmarks
of the disease.

A few hours in, the rapidly multiplying
bacteria start to release toxins,

leading to septicemia,
also known as blood poisoning.

This breaks down blood vessels,

letting blood seep out and form what
starts out looking like a rash,

and evolves into big discoloured blots
beneath the skin.

At the same time, these toxins
burn through oxygen in the blood,

reducing the amount that gets to
major organs like the lungs and kidneys.

That increases the chance
of organ shut down

--and alongside spreading
septicemia, threatens death.

That all sounds scary, but doctors are so
good at treating meningitis

that a visit to the hospital can drastically
reduce an adult’s risk of dying from it.

The longer it’s left
untreated, though,

the more likely it will lead
to lasting damage.

If declining oxygen levels cause cell
death in extreme parts of the body

--like fingers, toes, arms and legs--
the risk of amputation goes up.

And if bacterial toxins accumulate
in the brain and trigger cell death,

meningitis could also cause long-term
brain damage and memory loss.

So fast treatment, or better yet,
prevention, is critical.

That's why most countries have
vaccines that defend against the disease

in its deadliest forms.

Those are usually given to the people who
are most at risk--like young children,

people with weak immune systems,
or people who gather in large groups

where an outbreak of meningitis
could potentially happen.

In addition to those gatherings,

meningitis is most common in
a region called the meningitis belt

that stretches across Africa, though cases
do happen all over the world.

If you’re concerned that you or someone
you know may have meningitis,

get to the doctor as soon as possible;

quick action could save your life.