[Music]
I would like to start this talk with
a brief reflection on the
contrasts of our time
technology has advanced so much that
we can send missions to planets that
they are thousands of kilometers away
distance
or we can also build nano
cameras capable of visualizing what
is happening inside of us with
all the luxury of details and yet
we are still vulnerable to the
attack of some biological entities
infinitely smaller than
us and they do not even come to be
considered living beings
I am referring to viruses not only
we are worried about those who are already old
known as the flu but
practically every year there is an alert
about a new virus or about others that
without being new
we had never considered them a
threatens to consider them exclusive of
other places in the world among viruses
new
perhaps the best known is the virus
of AIDS
this virus was not known until the
80s when it started to cause
infections among communities of
homosexuals of san francisco and new
york
however, the virus was already
circulating several decades in africa
without us being aware
I remember many years ago I was
biology student in the faculty and
at that time it was discovered that the
cause of that disease that we call
AIDS was a virus and then my teacher
of virology moment in class
we can be calm has been
discovered that the cause of AIDS is
a virus so nothing will happen
in a couple of years we will have a vaccine
vaccine and AIDS will be controlled
however, several
decades
we still do not have the vaccine and not only
that the virus has demonstrated its ability
to become resistant to most
drugs but to all that have been
designed in front of him
in fact right now the treatments
anti-AIDS consist of cocktail of
drugs that have to be
supplied simultaneously to be able
have controlled the virus
another virus that worries us
recently most of all is Ebola
recently we thought it was ebola
movie virus and that we did not have
no risk of catching Ebola unless it’s
that we travel to Africa or some country
is the quite exotic indeed
first Ebola epidemic will not have
place until the year 1976 in Sudan and
zaire and as I say we were very
calm in our first world
however in the last epidemic of
Ebola about two years ago
we were not so calm
we started to have a little more
scared because we realized what
easy that is that a virus that
we consider ourselves very far away from us and
that can do us no harm in
some time may be a threat
real
we continue with other viruses the virus of
flu influenza virus to all
we think it’s good we ‘ve all
gone through nothing happens not but yes
that we know that the flu is not like the
agricultural measles we can catch
several times in our life that are the
that wants to tell us that it is a virus that
Changes a lot
we also know that we have
vaccinate and vaccines that have to be
change them every year to be
effective
but in addition to those changes the virus of
the flu is sometimes capable of
experience changes much more
drastic viruses that those with what
they turn into a much more virus
aggressive as happened for example in
1918 with the Spanish flu virus
which caused the order of 50 million
dead
more recently there have been other strains
of the flu virus there have been other
variants of this virus that have not been
so aggressive or that caused
pandemics
but what we can be sure of is
that humanity is never going to get rid
of the flu and that is always going to
there is a risk that a
new virus that can really
do a lot of damage
finally to end this
virus description I would like
talk about a virus that also
there is a lot of talk recently about how they are
virus cites dengue virus or virus
chikungunya these viruses are transmitted
by mosquito bites and
also how it happened with the Ebola virus
long ago it was thought that those
viruses could only be caught in the
areas occupied by those mosquitoes
frequently the tropical areas
however these mosquitoes currently
they are expanding in other regions
of our planet and that makes now
same these viruses there is a risk of
contract them in many other places
before all these situations it is logical
that we ask ourselves certain questions like
where these viruses come from or why
viruses that were previously located in
very specific regions
suddenly they have begun to occupy
much wider regions or because the
viruses are so resistant to all
strategies that we design in front of
them to answer these questions
of course we have to think about
characteristics of the viruses themselves
but we also have to think about
other characteristics that are derived
of the fact that the earth is a
gigantic ecosystem in which all
living beings are related ones
with others
good of its own kind or of other
species
inside this gigantic map of
interactions there are some that are
tremendously important and of those
many times we are not aware and
are the ones we establish with the
bacteria and with viruses
in fact viruses are the entities
most abundant biological
planet there is the order of 10 to 30 and a
virus
if someone can imagine that what I
say because it is a number that I think
impossible that our mind can
address the videos are all the
parts any surface that we touch
it is full of viruses
however, most of the time
the viruses do not do anything to us
we make sick
then we can ask what
it depends that he did come into contact with
a virus causes me illness or does not
cause to respond to this we need
explain a little bit how is the
dynamics of our interaction with
the virus
the viruses are very simple they are not anymore
that a fragment of genetic material
surrounded by a protective cover
protein that protects it and outside of
cells
viruses are not able to do anything
they are there and you’re not doing nothing
can be played
however when they find a
cell with an appropriate receptor to which
the virus can bind the virus going to
get inside that cell was going to
take advantage of the resources that the
cell to produce copies of yes
same
those copies are going to be released and they’re going to
happen to infect other cells other
organisms and in this way goes
transmitting the infection
that use of resources
cell phones is what many times we
cause the disease
let’s see now what happens at the level of
population is when infections by
a certain virus are very frequent
in a population what happens is that a
throughout evolution in that
population are selected
organisms that better resist the
infection by this virus because at
better because your immune system produces
better antibodies just at
over time it is what is left over you
time evolution because those organisms
manai being more abundant in the
population until the time came
that the population is composed
mostly by organisms that are
resistant to the virus
at that time the virus would stop
to infect us here, the
history there if it were not because the
viruses have in their possession a very
powerful that its great capacity for change
its great capacity for evolution
every time a virus enters a
cell every time a virus gets
multiply what you are going to do with something that
it can be a negative and it is
that is wrong very much produces many
mistakes
so that all the copies that
produces are different from each other and
also different from the original virus
so that virus populations are
tremendously heterogeneous populations
and in a population so heterogeneous with
mason genius as are the viral
it is very possible that a virus may emerge
that is not recognized by the
antibodies of your immune system cd
when that happens that virus is going to have
a tremendous advantage again will be
selected to start being
controlling
and that virus will be able to cause again
infections in the population the
repetition of many of these cycles to
over time is what is called or
evolution and coevolution what
supposes this a continuous race in 3
our immune system and the viruses to the
that our immune system faces
evolves to be more effective against
to viruses but in return viruses
they also evolve to be more
resistant to our system
immune sometimes also viruses
they evolve to reduce their aggressiveness
and not kill glued to the species
that infects because we can not forget
that for a virus
your world is the cell to cell dies
The virus also just
then it is logical to see them
favored viruses that are not so
aggressive
so over time there are
species that reach a coexistence
peaceful with certain viruses that is to say them
they allow themselves to multiply inside
and in return the virus does not hurt them or
it does them very little does not produce them
Symptoms of illness for example
wild waterfowl are the
reservoir is what they are called
species that reach that coexistence
peaceful are the reservoir as I say
of the influenza virus all the viruses of
the flu have entered the species
human always its origin
will be in bird viruses like no
we can charge all the birds
that’s why he has said that we will never be able to
end the flu many primates do not
humans are carriers of virus
immunodeficiency that if they pass to
humans can cause diseases so
serious as AIDS
bats are carriers of
many viruses including the Ebola virus
rodents are also carriers
many viruses like for example the sings
virus that causes hemorrhagic fevers the
problem happens when one of these
virus well adapted to your reservoir to
infect a different species when
that happens the rule almost always
fulfilled is that the new species
infected will produce a
much more serious illness because
because there has not been that period of
evolution with the immune system of
new operator and the virus has not been
attenuated has not reduced its virulence
this is happening continuously and
many times that only means a
risk to the person who contracts the
virus to be a risk to the
population
that virus has to be transmitted between
people and that sometimes can not do it
but over time throughout
evolution as viruses go
Changing
if they will be selecting the viruses that
better they are transmitted and a
moment we meet with a
new disease in our species that
they are called emerging diseases
for example let’s take the case of the virus
of AIDS and the AIDS virus is a virus
that has its origin in a virus of the
immunodeficiency of the apes that
affected chimpanzees this virus
probably entered the species
human when a hunter term this one to
scene to an infected chimpanzee to
consume it because this is very common in
Africa and thus introduced the
virus inside
surely at the beginning that virus does not
was adapted to multiply in the
human cells was adapted to the
simce cells and then it
it would multiply badly but little by little
were emerging viruses that replicated
the best and at the time that a
virus that multiplied better that
virus was that was the one that started
abound more in the population until
the virus was changing so that from a
virus
originally designs we went to
get a typically human virus is
what makes viruses get out of
your normal maintenance cycles in
the nature then any king factor
that alters those interactions that
we establish well with animals or
well with other organisms of our
same species can be from a
trigger of a new disease
viral for example the domestication of
animals took with him the introduction
of many viruses the human species virus
that right now we consider ourselves
normal and usual for us but
that really
our species came in when
we begin to live with the animals
when the domestic moss
climate change is also
having as a consequence that certain
viruses that were previously restricted to
very specific regions because they are now
distributed in much more regions
and, for example , can accommodate the
Dengue fever in regions where before
they were totally free from the plain has
also said for example hunting the
the risk that the hunter will
is affected by the viruses of its prey
as has happened with the case of the virus
of AIDS
when we talk about interactions
among the members of our species
when these increase we are
greatly favoring adaptation
of the virus to the human species because
the more times you can multiply
the virus the virus the more capacity there will be
that these variants arise better
adapted
we return to the virus of AIDS and the virus
of AIDS has said between the species
human by hunting but hunting is
something that is practiced in Africa
for millennia and yet we have
had AIDS until the 20th century
because the AIDS virus has had to pass
to our species a lot of times and
however , it has turned us into a
illness until scarce decades ago
because the 21st century before because in the
twentieth century in africa there were great
changes
it was the time of the colonizations was
the era in which there were migrations
massive from the countryside to the city
large vaccination campaigns in the
which the same needle was used to
Maybe vaccinate 100 people
imagine and the uca was infected is
say that increase in interactions
between humans
is what made AIDS aroused in the
twentieth century and not before
even if the virus had not entered
several times in our species
within these relationships between
members of our species I would like
stop me a moment in relationships
between members of different communities
because these relationships put us in
contact with viruses against those who
our immune system is not
used to interact for example
as historical examples we can quote
it’s about slaves that fever came
yellow america or the conquest itself
from america that put the
indigenous people with the viruses that they carried
the colonizers in this 20th century
good excuse we are in the 21 but already
in recent years travel in
plane are putting very clearly
manifest as viruses that arise in
places very far away in a short time
they can affect us
I would like to comment a little more about
this because when we talk about viruses there
we can think that because we live in
some regions where we have access
to vaccines and medicines we are free
of them if in the world we keep
region regions where poverty
it is a constant where there are no services
of sewage where you live with
animals
we will be favoring the adaptation of
many viruses to the human species and in a
world as interconnected as the current
those viruses can affect us in
any time
let’s not forget that the AIDS virus
had been circulating for a long time
Africa without us having been given
account and its adaptation to the species
human made her there in africa
therefore ours is by mutual selfishness
we have to try to beat the
infectious diseases
where they arise in the most places
poor of the planet
and finally I would like to end
a reflection the viruses carry in
our planet since there was the
lifetime
first about 3,800 million
years compared to that being
human is a newcomer to the earth
throughout all this time the viruses
they have made use of their great weapon their
ability to evolve to do
in front of all the circumstances
adverse that beings have been found
humans
instead we evolve more slowly
but we also have a very weapon
powerful that is our mind
that’s why the best thing we can do to
fight against viruses is to follow
investigating and being alert in front of
any change in the patterns of
how diseases are transmitted not
we can forget that any virus that
is being broadcast right now
silent form
in a village in Africa can be a
real and powerful threat to the future of
thank humanity
”
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