Bird flu. European/Asian problem, at least potentially.
Fear is that avian flu infecting humans could mutate with carried human flu genes, become human-human transmissable and thus cause a new global pandemic (some estimates are as high as 150m deaths ala the 1919 Spanish flu pandemic which killed 20-40m).
Human infections are mostly within the Asian regions; the likes of Thailand, China, etc. However, migrating wild birds with the virus have led to cases detected in Turkey and Greece.
The estimated death toll in the UK from an outbreak is, IIRC, 50,000.
However, all that is dependent upon a mutation into a human transmissable disease; that may happen tomorrow, or never. As it stands, the lack of such a mutation has the side-effect of making it impossible to develop a vaccine.