Pathogens evolve and cause emergent diseases)Provide a SPECIFIC example of an emergent disease, including its most probable original source.

One specific example of an emergent disease is the Ebola virus disease (EVD).

Step 1: Identifying the Disease The Ebola virus disease, also known as Ebola hemorrhagic fever, is a severe, often fatal illness in humans. It is caused by the Ebola virus, which is a member of the Filoviridae family.

Step 2: Understanding the Disease The disease was first identified in 1976 in two simultaneous outbreaks, one in Nzara, Sudan, and the other in Yambuku, Democratic Republic of Congo. The latter occurred near the Ebola River, from which the disease takes its name.

Step 3: Identifying the Source The exact origin, locations, and natural habitat (known as the "natural reservoir") of the Ebola virus remain unknown. However, on the basis of available evidence and the nature of similar viruses, researchers believe that the virus is animal-borne, with bats or nonhuman primates (chimpanzees, apes, monkeys, etc.) being the most likely source.

Step 4: Understanding the Transmission The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and indirect contact with environments contaminated with such fluids.

Step 5: Emergence of the Disease The Ebola virus disease is considered an emergent disease because it was not known prior to the 1976 outbreaks and has since caused several epidemics in Africa. The largest outbreak to date occurred in West Africa from 2014 to 2016, which resulted in more than 28,000 cases and more than 11,000 deaths.