Editing Epidemic (section)

=== Seasonality ===
Seasonal diseases arise due to the change in the environmental conditions, especially such as humidity and temperature, during different seasons. Many diseases display [[seasonality]],<ref>{{Cite journal |last=Martinez |first=Micaela Elvira |date=8 November 2018 |title=The calendar of epidemics: Seasonal cycles of infectious diseases |journal=PLOS Pathogens |language=en |volume=14 |issue=11 |pages=e1007327 |doi=10.1371/journal.ppat.1007327 |issn=1553-7374 |pmc=6224126 |pmid=30408114 |doi-access=free }}</ref><ref>{{Cite web |date=8 November 2018 |title=Mark Your Calendar: All Infectious Diseases Are Seasonal |url=https://www.publichealth.columbia.edu/news/mark-your-calendar-all-infectious-diseases-are-seasonal |access-date=13 September 2023 |website=Columbia University Mailman School of Public Health |language=en}}</ref> This may be due to one or more of the following underlying factors: -<ref>{{Cite journal |last1=Grassly |first1=Nicholas C |last2=Fraser |first2=Christophe |date=7 October 2006 |title=Seasonal infectious disease epidemiology |journal=Proceedings of the Royal Society B: Biological Sciences |volume=273 |issue=1600 |pages=2541–2550 |doi=10.1098/rspb.2006.3604 |issn=0962-8452 |pmc=1634916 |pmid=16959647}}</ref>
* The ability of the pathogen to survive outside the host - e.g. [[Waterborne diseases|water-borne]] cholera<ref>{{Cite journal |last=Leitzell |first=Katherine |date=20 November 2011 |title=The Time of Cholera |url=https://www.earthdata.nasa.gov/learn/sensing-our-planet/the-time-of-cholera |journal=NASA Earthdata |language=en}}</ref> which becomes prevalent in [[Monsoon|tropical wet]] seasons, or influenza which peaks in temperate regions during winter.<ref>{{Cite web |last=CDC |date=2022-09-20 |title=Learn more about the flu season |url=https://t.cdc.gov/C03 |access-date=2023-09-13 |website=Centers for Disease Control and Prevention |language=en-us}}</ref><ref>{{Cite journal |last1=Marr |first1=Linsey C. |last2=Tang |first2=Julian W. |last3=Van Mullekom |first3=Jennifer|author3-link=Jennifer Van Mullekom |last4=Lakdawala |first4=Seema S. |date=January 2019 |title=Mechanistic insights into the effect of humidity on airborne influenza virus survival, transmission and incidence |journal=Journal of the Royal Society Interface |language=en |volume=16 |issue=150 |pages=20180298 |doi=10.1098/rsif.2018.0298 |issn=1742-5689 |pmc=6364647 |pmid=30958176}}</ref>
* The behaviour of people susceptible to the disease - such as spending more time in close contact indoors.<ref>{{Cite web |last=Robson |first=David |date=19 October 2015 |title=The real reason germs spread in the winter |url=https://www.bbc.com/future/article/20151016-the-real-reason-germs-spread-in-the-winter |access-date=14 September 2023 |website=www.bbc.com |language=en}}</ref>
* Changes in immune function during winter - one possibility is a reduction in vitamin D, and another is the effect of cold on mucous membranes in the nose.<ref>{{Cite web |last=Kashef |first=Ziba |date=2019-05-13 |title=Flu virus' best friend: low humidity |url=https://news.yale.edu/2019/05/13/flu-virus-best-friend-low-humidity |access-date=2023-09-13 |website=YaleNews |language=en}}</ref><ref>{{Cite web |last=LaMotte |first=Sandee |date=6 December 2022 |title=Scientists finally know why people get more colds and flu in winter |url=https://www.cnn.com/2022/12/06/health/why-winter-colds-flu-wellness/index.html |access-date=2023-09-14 |website=CNN |language=en}}</ref>
* Abundance of vectors such as mosquitoes.<ref>{{Cite book |last1=Medicine |first1=Institute of |url=https://books.google.com/books?id=lDClwYeJdCEC |title=Vector-Borne Diseases: Understanding the Environmental, Human Health, and Ecological Connections: Workshop Summary |last2=Health |first2=Board on Global |last3=Threats |first3=Forum on Microbial |date=2008-03-18 |publisher=National Academies Press |isbn=978-0-309-17770-2 |language=en}}</ref>