[manicgeek]

As the planet warms there must be virii and bacteria that hasn't been around for generations being released back into the unsuspecting world, that flu pandemic in 1918 springs to mind. That virus must still be around, frozen in the wastelands, which must now today be thawing out... releasing the virus back into the wild, and then there's all those nasty bugs we got rid off with vacination programs... are they still out there frozen... waiting for their parole hearing... waiting to pounce on an unsuspecting mankind... to cause global panic and fear (sounds like something a global corporation would do doesn't it LOL ).

So how much longer will it be before we see something nasty ?

MODS I wasn't sure where to put this, if you feel it'd be better somewhere else, please feel free to move it :-)

[another_someone]

The flu virus of 1918 may still be around, but not much of a threat because we as a species have changed, and have developed some immunity to it (the problem with 1918 is that we had never encountered the virus before, so had no previous immunity to it).

A similar issue arose when Europeans started to colonise other continents, and spreading European diseases to which they had developed some partial immunity to the native populations had no previous immunity because they had never previously been exposed to the disease.

Whether we will lose that immunity after prolonged non-exposure depends on the genetic cost we had to pay to develop the immunity in the first place.

Incidental point of pedantry - the plural of virus is viruses.  The original Latin meaning of virus was a poisonous slime, and so had no plural (at least, none has ever been documented), so the English plural is applied to the word that had no Latin plural.

The only disease that we as a species have eradicated is smallpox.  Other diseases have been eradicated in certain environments, mostly within the richer countries, while still existing in the poorer parts of the world.

[manicgeek]

But have we really eradicated smallpox... or is it lying dormant... waiting to come back in some mutated form... after a couple of generations of laying dormant, how do we know that it's not mutating as it thaws and that it's new form won't be something even nastier... just laying there waiting for us ?

It's like something out of a Hitchcock movie... the suspense is killing me... Heehee!

I stand corrected on my use of virii... although I might come to regret that, there are some pretty nasty men about as well... no thawed out ones though  []

[another_someone]

But have we really eradicated smallpox... or is it lying dormant... waiting to come back in some mutated form... after a couple of generations of laying dormant, how do we know that it's not mutating as it thaws and that it's new form won't be something even nastier... just laying there waiting for us ?

Yes and no.

Smallpox only lives in the human host (which is why we could eradicate it - because there is no animal reservoir for the disease), and I don't believe it can survive long outside the human body (it was only ever transmitted by human to human contact, and could not be transmitted from corpses).

One should also stress that any diseases causing agent is dormant, then by definition, it cannot mutate - so the problems of mutation do not arise.

The 'yes' is that there is still a strong possibility that the smallpox virus is still in existence in various research establishments (at least, military, if not civilian - the last recorded death from smallpox was from a leak from just such a research establishment).

The problem is that the real risk is not from frozen samples of pathogens (even if they did survive, it would be in too small a quantity to be a real threat), but from new diseases from animals (such as Ebola, Marburg, bubonic plague, and even HIV started from SIV in apes).

The problem with flu is that it so easily jumps between pigs, birds, and man - hence the fear about avian flu (although avian flu still needs to make mutation to make it efficient in using man as a host, but the flu virus is very good at mutating).