Pneumonic plague.
It's going around, currently there is an outbreak in Madagascar.
I'll bet terrorists would love to get this going in the general population.
</TIN FOIL HAT ALERT>
I'll bet the CDC and quite possibly USAMRID already are engaged.
I’m a little worried about the Madagascar plague too. The mullahs could have sent the infected all over the Christian world. I’ll get a whole lot more worried when mysterious flu-like deaths start showing up elsewhere.
Tinfoil scenario B is a person returning home from vacation in Madagascar with the plague.