COVID spread didn’t break down into first world vs third world countries because first world countries infrastructure isn’t built with pandemics in mind.
Instead a great deal of modern infrastructure like subway systems makes things more difficult not less.
This gets into the question of definitions vs edge cases.
Ebola like many viruses can be contagious without direct touching.
It’s not well adapted to airborne transmission, but it’s very good at causing people to spread bodily fluids all over the place. So a very sick individual passing through a subway seeking medical treatment could infect a large number of people.
Instead a great deal of modern infrastructure like subway systems makes things more difficult not less.