SAARS, Dengue fever, West Nile, AIDS...this record is definitely broken. The Spanish flu flourished and spread so quickly due to a non-existent pathognic containment policy and the crowded and squalid conditions of cities like Chicago, New York and Boston. But those facts aren’t sexy and don’t somehow jive with the position that we shouldn’t be in Iraq and that the money should be put into an even larger government bureaucracy to protect us from the new "Pandemic".
You should also consider the fact that like the Spanish flu, we (none of us) has even the smallest bit of natural immunity. We live in a much smaller world today than the people of 1918. If this thing learns to jump from human to human, you couldn't shut down international travel fast enough to stop it.
And in the case of a disease that transmits from human to human, squalid conditions are irrelavent. The only condition that matters is how close one group of people is to the next and there is no doubt at all that we live closer to our neighbors today than we did in 1918.