That’s a nice scenario for a thriller movie, but in reality, I just don’t think terrorists are smart enough to pull off such a scenario. Whether it would even work is another thing. Doesn’t an explosion involve a lot of very high heat? I’m not sure any virus would survive that.
No.
There are bombs for biological agents. What’s key is that even with an explosion, with few exceptions, often the explosion doesn’t provide heat for a long enough duration to kill the germs. If not a bomb, well, a disguised water bottle perhaps.
“Whether it would even work is another thing. Doesn’t an explosion involve a lot of very high heat?”
Although explosives do provide a short-lived high temperature blast to their immediate surroundings that is definitely not sufficient to sterilise shards of bomb casing or shrapnel etc.
For example, in Afghanistan the Taliban often cover the outside of their IEDs with human or animal shit. The effect of this is that people who are injured in such a blast, in addition to loosing limbs, get septiciemia and need antibiotic treatment to survive.
However, you are correct that viruses are much more thermolabile than pathogenic bacteria. Although, if an explosive was detonated inside an infected human body there would be much more protection from the blast heat for billions of filoviruses, so I would not dismiss this as a possible threat.
But on the other hand, ISIL are a bunch of knuckle-dragging Islamist neanderthals so I sincerely doubt that they could actually implement such a thing in the USA.