Yes, humans are considered a natural reservoir for Ebola. This is because so many of them have contracted this deadly virus.
Ebola
Ebola is caused by one of four Ebola viruses: Ebola Zaire (most deadly), Ebola Sudan, Ebola Cote d' Ivoire, and Ebola Reston (found in Virgina, US, not deadly to humans)
Ebola seems to be infective exclusively to mammals and especially primates. It produces a high degree of morbidity and mortality in humans, green monkeys macaques, and others. Fruit bats have also been found to harbor indications of Ebola exposure in their livers, but it is thought that bats are not the vector, but actually suffer from the disease itself. The current guess (and it is no more than a guess at this time) is that the reservoir for Ebola may possibly be a long-lived arthropod, but this guess is based on circumstancial evidence and not clinical examination.
No. They're different. I believe Ebola is contagious between humans, while cancer is not.
There are about five strains of Ebola. Four infect monkeys and the fifth is found in fruit bats and now has infected humans. The monkeys can get Ebola like they can get many viral diseases and that is because there are proteins on the surface of the cells of the monkeys that the virus can attach to.
Humans are the only known reservoir for the mumps virus
2 humans and 2 dogs.
Fruit bats and other primates as well as humans can get Ebola. But there is no epizootic cycle for humans. That means that it can be spread from human to human without any carrier (animal).
Ebola hemorrhagic fever (alternatively Ebola Haemorrhagic Fever, EHF, or just Ebola) is a very rare, but severe, mostly fatal infectious disease occurring in humans and other primates, caused by the Ebola virus, which is possibly carried by fruit bats.
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.
As far as we know, Ebola attacks mostly primates. There is some indication that it may also attack the Afrtican Fruit Bat (and by inference, other mammals as well). Some variants of Ebola, notably Ebola reston, were lethal to monkeys but apparently infected humans although -- in humans -- it remained asymptomatic. Bear in mind that we suspect Ebola has been misdiagnosed quite often, as its symptomology is very similar to many other disorders indigenous to Ebola locale.
There is ample evidence that ebola is a naturally-occurring virus. There are many animals with antibodies to ebola and similar viruses. It is human nature to look for a conspiracy to explain such a natural force, but there is no science behind the belief that ebola is man-made.