Why is meningitis so dangerous? - Melvin Sanicas

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 gasses. 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, those 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.