gsgs
Registered User
since when is there influenza in humans ?
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it clearly was not much of a concern for people in ancient times.
some musings:
---------------------------------
In the year 412 BC Hippocrates described an
epidemic that modern doctors believe was influenza,
and history has recorded many influenza epidemics
and pandemics since that time.
In the Middle Ages several widespread outbreaks
that were probably influenza occurred in Europe. But
the first epidemics that can be regarded with confi-
dence as influenza were in 1173. However, the
position of some medical historians that only
epidemics which occurred in 1510 can be considered
as unquestionable influenza epidemics [1]. In 1580
a severe pandemic occurred that was possibly the first
global dissemination of influenza
-----------------------------------
that last one has recently supposed to have been pertussis.
So, no global dissemination of influenza before 1580 ?
Maybe a pandemic needs advanced human travel methods
or high human population.
Influenza pandemics show the pattern of a new virus
establishing in humans which destroys the previously existing
human flu-A viruses. The evolution starts new from that point.
The avian virus evolves and becomes more human like.
This was what we have since 1918. The 1957,1968 events
were just a rearrangement of 1918-genes with additional
H3 or H2 genes newly acquired from birds.So 80% of todays
viruses is still from 1918. We can clearly watch the evolution and
how the virus became more and more human-like through
the last 80 years.
In birds, where flu usually resides it's different. You can see a more
uniform picture of all sorts of co-existing viruses with large variety
and without clear origin.
So, the pattern of evolution of flu in humans is different.
And presumably quite new. We won't expect these cycles
of new-introduction from birds with pandemic and wiping out of earlier
strains, then evolution and adaption in humans which makes the virus
quite distinct from all avian viruses.
And then after 100 years or such another pandemic which wipes out the
old viruses.
This doesn't seem to be a stable cycle which we could expect to be going
on since thousands of years.
If all flu in humans earlier or later is wiped out by a new strain
which comes from birds - then there is basically no continuous evolution
in humans. Humans are just not important for flu.
It's an "accident" when humans are infected.
Unless the virus jumps back from humans to birds and gives
acquired mutations to birds. But this doesn't seem to be the case.
So also this fight of human immunity against viruses who
escape by mutating quickly, by reassorting, by developing 16 different
HAs is it really driven by human-virus evolution ?
There just wasn't enough time since 1500 or such for
human genetical changes. And the virus doesn't need humans,
it evolves in birds.
how can it be an advantage for a virus when it is also capable
of infecting humans, binding to alpha 2-6, etc. when earlier or later
it is being wiped out by a new pandemic,avian virus anyway ?
were mammals important in the history of flu-development ?
(thinking in millions of years here)
--------------------------------------------------------------------------------
it clearly was not much of a concern for people in ancient times.
some musings:
---------------------------------
In the year 412 BC Hippocrates described an
epidemic that modern doctors believe was influenza,
and history has recorded many influenza epidemics
and pandemics since that time.
In the Middle Ages several widespread outbreaks
that were probably influenza occurred in Europe. But
the first epidemics that can be regarded with confi-
dence as influenza were in 1173. However, the
position of some medical historians that only
epidemics which occurred in 1510 can be considered
as unquestionable influenza epidemics [1]. In 1580
a severe pandemic occurred that was possibly the first
global dissemination of influenza
-----------------------------------
that last one has recently supposed to have been pertussis.
So, no global dissemination of influenza before 1580 ?
Maybe a pandemic needs advanced human travel methods
or high human population.
Influenza pandemics show the pattern of a new virus
establishing in humans which destroys the previously existing
human flu-A viruses. The evolution starts new from that point.
The avian virus evolves and becomes more human like.
This was what we have since 1918. The 1957,1968 events
were just a rearrangement of 1918-genes with additional
H3 or H2 genes newly acquired from birds.So 80% of todays
viruses is still from 1918. We can clearly watch the evolution and
how the virus became more and more human-like through
the last 80 years.
In birds, where flu usually resides it's different. You can see a more
uniform picture of all sorts of co-existing viruses with large variety
and without clear origin.
So, the pattern of evolution of flu in humans is different.
And presumably quite new. We won't expect these cycles
of new-introduction from birds with pandemic and wiping out of earlier
strains, then evolution and adaption in humans which makes the virus
quite distinct from all avian viruses.
And then after 100 years or such another pandemic which wipes out the
old viruses.
This doesn't seem to be a stable cycle which we could expect to be going
on since thousands of years.
If all flu in humans earlier or later is wiped out by a new strain
which comes from birds - then there is basically no continuous evolution
in humans. Humans are just not important for flu.
It's an "accident" when humans are infected.
Unless the virus jumps back from humans to birds and gives
acquired mutations to birds. But this doesn't seem to be the case.
So also this fight of human immunity against viruses who
escape by mutating quickly, by reassorting, by developing 16 different
HAs is it really driven by human-virus evolution ?
There just wasn't enough time since 1500 or such for
human genetical changes. And the virus doesn't need humans,
it evolves in birds.
how can it be an advantage for a virus when it is also capable
of infecting humans, binding to alpha 2-6, etc. when earlier or later
it is being wiped out by a new pandemic,avian virus anyway ?
were mammals important in the history of flu-development ?
(thinking in millions of years here)