I think that H5N1 is a far, far greater and more immediate threat to all of humanity, including Americans, than any terrorism. Talk about clear and present dangers.

ABUJA, 8 February (IRIN) - Tens of thousands of chickens have died of the killer bird flu virus in northern Nigeria, the first confirmed cases of H5N1 in Africa, the International Organisation for Animal Health (OIE) said on Wednesday.

West Africa lies on the migratory path of birds that may already be affected with avian influenza. And the region is littered with ecologically important reserves where birds flock to seek warmth during the northern hemisphere winter.

Reuters

And:

Reports this summer and fall of the spread of the H5N1 strain strongly suggested wild birds were carrying the disease outward from Asia as they followed migration patterns that crisscross the Earth. The timing and location of outbreaks in western China, Russia, Romania, Turkey and Croatia seemed to point to wild birds en route to winter grounds.

That put places like Alaska, where birds from the Old and New Worlds gather each summer to create what some call an “international viral transfer center,” on alert that the virus could arrive this coming spring. And from there, species like the buff-breasted sandpiper and others that split their time between North and South America could in theory transport the virus farther afield.

MSNBC

The last article, dated Dec. 28, 2005, points out that migratory birds don't seem to be spreading H5N1, but not with complete certainty. The outbreak in Nigeria may revive that theory, in which case the disease could be worldwide by spring.

The more times H5N1 comes in contact with humans, the greater the risk of mutations that would allow human-to-human transmission.

This is a disease with, so far, a greater than 50% mortality rate, as compared to about 5% for the 1918 pandemic that killed at least 20 million. I have yet to see any statement to indicate that the lethality of H5N1 would most likely decrease when it does adapt to inter-human spread - as far as I have been able to determine, the opposite could just as easily be the case, with lethality increasing.

The world is vastly different now that it was in 1918 - medical science has progressed tremndously, so fighting the disease on an individual basis should be more effective. However, there are a lot more people now, many living in crowded and unsanitary conditions in close proximity to fowl, and mobility is much, much greater than it was in 1918... then, it would have taken many weeks for people to travel around the world; now, it's a matter of hours.

I think two billion deaths is not impossible. It would mean a totally different world.