Editing Epidemic (section)

=== Changes in transmission ===
[[File:Anopheles gambiae mosquito feeding 1354.p lores.jpg|thumb|Anopheles mosquito, the vector of malaria]]
[[Pathogen transmission]] is a term used to describe the mechanisms by which a disease-causing agent (virus, bacterium, or parasite) spreads from one host to another. Common modes of transmission include:<ref>{{Cite web |title=FAQ: Methods of Disease Transmission |url=https://eportal.mountsinai.ca/Microbiology/faq/transmission.shtml |access-date=10 January 2024 |website=Department of Microbiology, Mount Sinai Hospital}}</ref> -
* [[Airborne transmission|airborne]] (as with influenza and COVID-19),
* [[Fecal–oral route|fecal-oral]] (as with cholera and typhoid),
* [[vector-borne]] (malaria, Zika) and
* [[Sexually transmitted infection|sexual]] (syphilis, HIV)

The first three of these require that pathogen must survive away from its host for a period of time; an evolutionary change which increases survival time will result in increased virulence.<ref>{{Cite news |last=Mandavilli |first=Apoorva |date=1 October 2021 |title=Is the Coronavirus Getting Better at Airborne Transmission? |language=en-US |work=The New York Times |url=https://www.nytimes.com/2021/10/01/health/coronavirus-aerosols-airborne.html |access-date=12 September 2023 |issn=0362-4331}}</ref>

Another possibility, although rare, is that a pathogen may adapt to take advantage of a new mode of transmission<ref>{{Cite journal |last=Alcamí |first=Antonio |date=2023-03-28 |title=Pathogenesis of the circulating mpox virus and its adaptation to humans |journal=Proceedings of the National Academy of Sciences |language=en |volume=120 |issue=13 |pages=e2301662120 |doi=10.1073/pnas.2301662120 |issn=0027-8424 |pmc=10068839 |pmid=36940331|bibcode=2023PNAS..12001662A }}</ref><ref>{{Cite journal |last1=Antonovics |first1=Janis |last2=Wilson |first2=Anthony J. |last3=Forbes |first3=Mark R. |last4=Hauffe |first4=Heidi C. |last5=Kallio |first5=Eva R. |last6=Leggett |first6=Helen C. |last7=Longdon |first7=Ben |last8=Okamura |first8=Beth |last9=Sait |first9=Steven M. |last10=Webster |first10=Joanne P. |date=2017-05-05 |title=The evolution of transmission mode |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |language=en |volume=372 |issue=1719 |pages=20160083 |doi=10.1098/rstb.2016.0083 |issn=0962-8436 |pmc=5352810 |pmid=28289251}}</ref>