The most severe symptoms are sudden onset.
You have a headache for a few days then out of the blue, projectile vomiting and diarrhea. THIS IS HOW IT SPREADS.
Like I said...contact.
Contact with another individual’s blood or fluids.
It’s not airborne.
In Africa it tends to propagate through families.
Since the mid seventies, only about 3 thousand have contracted it and that being in a densely populated place with some rather unusual social customs and poor hygiene to boot..
So I think we have more important things to worry about.