AHC: Isolated Smallpox in North America pre-1442

Your challenge, if you choose to accept it, is to have a massive population(10,000 to 50,000) with some smallpox enter North America pre-1442. As per "Isolated", they may not be able to send back for others or go back themselves. Please try to follow this up some. Good luck!

Forgive me for asking, but what is the significance of the year 1442? As for smallpox, I doubt you would have 'isolated' outbreaks. Once established, it would go thru the population like a scythe. Unless it only affected the people on one island in the West Indies, say, and didn't spread anywhere else.

Not fully isolated, but long-term trade through Vinland would almost certainly introduce smallpox by 1300 AD.

Once there, it would probably burn its way into the Mississippi valley and become permanently established there. From there it's only a matter of time until it reaches Mesoamerica, but this could take centuries-i.e. after an alt-history Columbian exchange is opened circa 1500 AD (which I think is what you want?)

oudi14 said:

Forgive me for asking, but what is the significance of the year 1442?

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I guess OP either meant 1492, or chose 50 years in advance as a good starting point.

Have one of the norse ships collecting lumber in vinland introduce the disease through extreme back luck (shipwreck), or minor trade...

You won't get "isolated" smallpox unless you have a situation where it is on an island or some piece of land with no connections with other populations. OTL once introduced, most of the smallpox spread amongst the native American population was due to contact between villages/tribes along normal trade routes etc. There was some accelerated spread due to the Europeans but once introduced smallpox will spread. Again, unless you have a small an isolated population, there will always be some lurking and a population that is susceptible. If you have an "island", you'll see smallpox go through devastating the population, survivors will be immune but with a small enough population you'll end up with the dead and the immune, and no reservoir for the disease. Smallpox has no animal host and doesn't survive in the environment (like Anthrax for example), therefore after it sweeps through it will be gone.

A "new world" exposed to smallpox before Columbus will have more or less the same massive death rate as smallpox spreads, and then become like Europe where you have periodic epidemics as the number of non-immunes rises (new births) and the low level of disease presence sets off another wave. Eventually selection will mean that the local population as more or less the same susceptibility to smallpox as the Europeans, smallpox still ~30%+ fatal, 5%+ significant permanent damage (not just scarring).

sloreck said:

A "new world" exposed to smallpox before Columbus will have more or less the same massive death rate as smallpox spreads, and then become like Europe where you have periodic epidemics as the number of non-immunes rises (new births) and the low level of disease presence sets off another wave. Eventually selection will mean that the local population as more or less the same susceptibility to smallpox as the Europeans, smallpox still ~30%+ fatal, 5%+ significant permanent damage (not just scarring).

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How early would this smallpox exposure in the Americas have to happen in order for the Indigenous population at the time of first contact (let's assume still 1492 for the sake of argument) to have recovered to pre-exposure level, with European-like immunity rates?

sloreck said:

Eventually selection will mean that the local population as more or less the same susceptibility to smallpox as the Europeans, smallpox still ~30%+ fatal, 5%+ significant permanent damage (not just scarring).

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20% fatal if the population is capable of spreading out more and self-quarantining. Combined with the fact that this epidemic will not be followed (in most places) by brutal land grabs and genocidal war, the population is actually liable to recover quite quickly. Recurring epidemics can be dealt with by further quarantining, and with immune survivors of the previous epidemics caring for new victims. That said, cultural practices such as sweat lodges may adversely effect people who catch the disease.

I agree with all of the above.

Vikings coming from Vinland are the most likely culprits of spreading the infection.

But there is no "isolating" smallpox. Once it is out, it is out. If it is "isolated", then why bother intrucing the butterfly?

Certainly, an epidemic of smallpox fifty years before Columbus would change alot:

1. Maybe the civilizations the conquestadors come to sack wouldn't exist and there would be no source of gold/silver without the labor force.

2. Maybe the tribes, with two to four generations of exposure might have developed some sort of immunity, though their numbers would be vastly reduced by the time Cortez showed up.

Does/did Smallpox mutate at the speed of some of the influenza strains? If it does mutate quickly, could a early arrival (via Vinlanders, or Portugese fisherman, or shipwrecked monks) lead to enough variation to put the early Conquistadors at risk?

That would be ironic...

Driftless said:

Does/did Smallpox mutate at the speed of some of the influenza strains? If it does mutate quickly, could a early arrival (via Vinlanders, or Portugese fisherman, or shipwrecked monks) lead to enough variation to put the early Conquistadors at risk?

That would be ironic...

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It's my understanding that smallpox actually doesn't mutate very rapidly. Hell, the variola virus has jumped species and the different strain still provides cross-immunity (cowpox, horsepox, etc.)

Smallpox does not mutate much if at all. The 30% death rate refers to the fatality rate in someone with no immunity (ie: previous disease or a vaccination {which fades with time}), this assumes no modern medical care. Things like quarantine only help slow the spread, they don't affect the outcome once you get sick.

It's hard to say how long it would take for the Native American population to end up with the same level of natural (as opposed to acquired) resistance to smallpox, but it would be quite a few generations at least (given ~20 yrs/per generation). Between the disease itself and the dislocation of farming and hunting, children left without parents etc, I would expect the Native American population to be reduced by at least 50%. Given it will be quite some time before "American" resistance reaches European levels, rebuilding the population will be quite slow. And, as mentioned, there will be periodic epidemics which will be worse than they would be Europe.

It should be pointed out that smallpox was not the only killer imported from Europe. Influenza and tuberculosis both were imported, and as with smallpox the native population had neither inherent resistance or acquired resistance. What this means, even if smallpox comes to the new world 200-300 years earlier and spreads, the indigenes will still be vulnerable to some other serious imported disease. In Native Americans, TB was not a lingering disease but one that progressed rapidly.