How does a virus affect humans?
A virus affects humans by invading a cell. The virus then forces the cell to produce viral material rather than cell material. This causes the cell to replicate the virus rather than itself.
Animal viruses don't affect all animals. One example is how rabies from bats isn't seen in all species of animals around (eg.) vampire bat feeding sites. Also, human viruses don't only affect humans. An example of this is how swine flu can be passed from pigs to humans and back again. Viruses all pretty much work the same, with virus DNA being inserted into a host cell, then replicating, and causing different effects depending on…
Ebola is caused by infection with a virus of the family Filoviridae, genus Ebolavirus. There are five identified Ebola virus species, four of which are known to cause disease in humans: Ebola virus (Zaire ebolavirus); Sudan virus (Sudan ebolavirus); Taï Forest virus and Bundibugyo virus (Bundibugyo ebolavirus). The fifth, Reston virus (Reston ebolavirus), has caused disease in nonhuman primates, but not in humans.