I have, for some time, been of the opinion that the threat of international terrorism is trivial when compared with the likes of global warming and the next viral pandemic.
According to a BBC report, the H5N1 strain of Avian Influenza Virus ("bird flu") has now appeared in the Urals - the sixth region in Russia so far to be affected.
All it will take is for a small mutation to allow H5N1 to jump the species barrier...
UPDATE/CORRECTION: H5N1 has crossed the species barrier; as yet, however, it is not transmissible human-to-human.
Smiffy at LinkedIn