Very few viruses
actuallykill people.
In general, it is
thehumanswho
kill themselves,
so to speak,
asaresultof
excessively severe
inflammation.
LINFAWANG,VIROLOGISTFROMSINGAPOREinside its body than are stored in all
the high-security laboratories of the
world combined.
Are fruit bats really so dangerous
for humans, or was this an extremely
unfortunate isolated incident? For
centuries people have been afraid
of bats. In recent years this fear has
increased. The reason: Doctors have
proved that these animals actually
do carry viruses that cause deadly
epidemics like Ebola—but they only
rarely transmit such viruses directly
to humans. “This only occurs when
someone is bitten by a fruit bat or
eats the meat of the creature,” says
Colorado State University infectious
diseases specialist Tony Schountz.
Or it can occur indirectly if an open
wound comes into contact with the
saliva, blood, or excrement of these
animals. Thus the question remains:
If fruit bats carry deadly pathogens
like the Ebola and Marburg viruses,
why don’t they get sick themselves?
In fact, researchers have now found
that while other animals and people
die from these viruses, fruit bats do
not even get a fever. On the contrary:
They live up to 10 times longer than
all other mammals of a comparable
size and they hardly ever get cancer.So, is the key to healing also to be
found in the body of these bats—the
same body that carries such deadly
cargo? Researchers are sure of it,
and they’re now trying to unlock the
secret of fruit bats’ immune system.
Their hope: Perhaps before too long
humans will have fruit bats to thank
for improving our health as well as
lengthening our lives...HOW DO YOU LIVE WITH A
DEADLY ENEMY IN YOUR BODY?
In order to achieve this, it must first
be understood how the bats can live
with these pathogens in their bodies.
Linfa Wang, director of the emerging
infectious diseases department at
the Duke-NUS Medical School in
Singapore, researched exactly that.
In order to examine fruit bats, which
can transmit the dangerous Hendra
virus to horses that can then pass it
on to humans, he spent almost two
decades in Australia. He found out:
Unlike other mammals, fruit bats can
control the virus. They don’t exhibit
a fever or an elevated level of white
blood cells in the blood or any other
defensive immune reaction. But how
does their immune system manage
to render the virus harmless?
One explanation: incredibly fast
metabolism while flying. Fruit bats,
which weigh up to 2.5 pounds, need
up to 20% more calories than non-
flying mammals do. However a fast
metabolism means plenty of free
radicals in the blood, and these can
damage DNA. To ensure this does
not happen, the immune system is
continuously operating at full blast.
It clears out dangerous molecules—
including potentially deadly viruses.
Because their immune system works
so well, the bats themselves do not
get sick. The virus multiplies in their
bodies and they pass it on to their
offspring—yet no symptoms occur.
But that’s not the case for people.
In the event of a comparable viral
invasion, our immune system wouldI
t is a small mishap that Sonia
Visser* will not even remember
until a few weeks later. In the
middle of the Ugandan jungle,
the woman stumbles while taking a
jungle tour, slightly injuring her hand.
She places her hand on a rock for a
moment to brace herself while she
regains her composure. It’s nothing
dramatic, she thinks, as she makes
her way to catch up with the group.
A tragic mistake...HOW DO YOU GET INFECTED
WITHOUT NOTICING?
Back in the Netherlands, the young
woman develops a high fever. Then
everything occurs frighteningly fast.
Sonia Visser is rushed to a hospital;
her organs are failing—and in a few
days she dies. She is a victim of the
Marburg virus, which is transmitted
by wild animals—even though she’d
never had contact with a wild animal.
How could that be possible? In fact,
the virus entered Sonia’s body when
she used her bloody hand to support
herself on that rock in the jungle—
and she inadvertently touched the
guano of a fruit bat. What she made
contact with were the droppings of
an animal that carries more virusesHIGHESTSECURITYLEVEL
Researchers test fruit bats for the Ebola virus.
The animals are eaten in Africa, and this likely
triggered the outbreak of the deadly disease.*NAME HAS BEEN CHANGED BY THE EDTIORS.Mar 2017 24 ideasanddiscoveries.com