> We would soon die out as a race due to population decline as we are well below the required rate of replacement in a diseased population

Isn't there a strong correlation between birth rate & child mortality? Most rich societies have slowed down their birth rate in large part because you don't need 5 kids in order to ensure 1 makes it to adulthood.

If we tolerated disease, we would probably increase birth rates to compensate for the spike in child mortality.