Zoonosis describes the process whereby an infectious disease is transmitted between species,usually to diseases that can travel from animals to humans. They include all diseases. Many serious epidemic diseases are zoonoses which originated in animals. These include rabies, Ebola virus disease and influenza. In a systematic review of 1,415 pathogens known to infect humans, 61% were zoonotic. The emergence of a pathogen into a new host species is called disease invasion or "disease emergence". The emerging interdisciplinary field of conservation medicine integrates human and veterinary medicine.
