Editing Epidemic (section)

=== Zoonosis ===
[[File:Figure 3- Examples of Zoonotic Diseases and Their Affected Populations (6323431516).jpg|thumb|Possibilities for zoonotic disease transmissions]]
A [[zoonosis]] is an [[infectious disease]] of humans caused by a pathogen that can [[Cross-species transmission|jump]] from a non-human host to a human.<ref>{{Cite web |date=29 July 2020 |title=Zoonoses |url=https://www.who.int/news-room/fact-sheets/detail/zoonoses |access-date=14 September 2023 |website=World Health Organization |language=en}}</ref> Major diseases such as [[Ebola virus disease]] and [[salmonellosis]] are zoonoses. [[HIV]] was a zoonotic disease transmitted to humans in the early part of the 20th century, though it has now evolved into a separate human-only disease.<ref name="Orgin2011">{{cite journal |vauthors=Sharp PM, Hahn BH |date=September 2011 |title=Origins of HIV and the AIDS pandemic |journal=Cold Spring Harbor Perspectives in Medicine |volume=1 |issue=1 |pages=a006841 |doi=10.1101/cshperspect.a006841 |pmc=3234451 |pmid=22229120}}</ref> Some strains of [[Influenza A virus subtype H5N1|bird flu]] and [[Influenza A virus subtype H1N1|swine flu]] are zoonoses; these viruses occasionally recombine with human strains of the flu and can cause [[pandemic]]s such as the [[1918 Spanish flu]] or the [[2009 swine flu]].<ref>{{cite journal |vauthors=Scotch M, Brownstein JS, Vegso S, Galusha D, Rabinowitz P |date=September 2011 |title=Human vs. animal outbreaks of the 2009 swine-origin H1N1 influenza A epidemic |journal=EcoHealth |volume=8 |issue=3 |pages=376–380 |doi=10.1007/s10393-011-0706-x |pmc=3246131 |pmid=21912985}}</ref>