Editing Tetanus (section)

== Cause ==
[[File:Clostridium Tetani.svg|thumb|''Clostridium tetani'' is durable due to its [[endospore]]s. Pictured is the bacterium alone, with a spore being produced, and the spore alone.]]

Tetanus is caused by the tetanus bacterium, ''[[Clostridium tetani]]''.<ref name=CDC2012Pink/> The disease is an international health problem, as ''C.&nbsp;tetani'' [[endospore]]s are ubiquitous. Endospores can be introduced into the body through a puncture wound ([[penetrating trauma]]). Due to ''C.&nbsp;tetani'' being an anaerobic bacterium, it and its endospores thrive in environments that lack [[oxygen]], such as a puncture wound. With the changes in oxygen levels, the turkey drumstick-shaped endospore can quickly spread.<ref>{{cite journal | vauthors = Hanif H, Anjum A, Ali N, Jamal A, Imran M, Ahmad B, Ali MI | title = Isolation and Antibiogram of Clostridium tetani from Clinically Diagnosed Tetanus Patients | journal = The American Journal of Tropical Medicine and Hygiene | volume = 93 | issue = 4 | pages = 752–6 | date = October 2015 | pmid = 26175031 | pmc = 4596594 | doi = 10.4269/ajtmh.15-0040 }}</ref>

The disease occurs almost exclusively in people who are inadequately immunized.<ref name="Baron">{{cite book|chapter-url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.1099|title=Baron's Medical Microbiology|publisher=Univ of Texas Medical Branch|year=1996|isbn=978-0-9631172-1-2|chapter=Clostridia: Sporeforming Anaerobic Bacilli|vauthors = Wells CL, Wilkins TD|pmid=21413315 |veditors = Baron S|url-status=live|archive-url=https://web.archive.org/web/20090206221707/http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.1099|archive-date=2009-02-06}}</ref> It is more common in hot, damp climates with soil rich in [[Soil organic matter|organic matter]]. [[Manure]]-treated soils may contain spores, as they are widely distributed in the intestines and feces of many animals, such as horses, sheep, cattle, dogs, cats, rats, guinea pigs, and chickens.<ref name=CDC2012Pink/> In agricultural areas, a significant number of human adults may harbor the organism.<ref>{{cite web |title=Pinkbook: Tetanus {{!}} CDC |url=https://www.cdc.gov/vaccines/pubs/pinkbook/tetanus.html |website=www.cdc.gov |access-date=28 September 2021 |language=en-us |date=17 August 2021}}</ref>

The spores can also be found on skin surfaces and in contaminated [[heroin]].<ref name=CDC2012Pink/> Rarely, tetanus can be contracted through surgical procedures, intramuscular injections, compound fractures, and dental infections.<ref name=CDC2012Pink/> Animal bites can transmit tetanus.<ref name=CDC2012Pink/>

Tetanus is often associated with [[rust]], especially rusty nails. Although rust itself does not cause tetanus, objects that accumulate rust are often found outdoors or in places that harbor soil bacteria. Additionally, the rough surface of rusty metal provides crevices for dirt containing ''C.&nbsp;tetani'', while a nail affords a means to puncture the skin and deliver endospores deep within the body at the site of the wound.<ref>{{cite web|url=http://science.howstuffworks.com/science-vs-myth/everyday-myths/rusty-nail-tetanus1.htm|title=Causes of Tetanus|website=HowStuffWorks| vauthors = Edmonds M |access-date=9 November 2015|url-status=live|archive-url=https://web.archive.org/web/20151122031152/http://science.howstuffworks.com/science-vs-myth/everyday-myths/rusty-nail-tetanus1.htm|archive-date=22 November 2015|date=2009-07-29}}</ref> An endospore is a non-metabolizing survival structure that begins to metabolize and cause infection once in an adequate environment. Hence, stepping on a nail (rusty or not) may result in a tetanus infection, as the low-oxygen (anaerobic) environment may exist under the skin, and the puncturing object can deliver endospores to a suitable environment for growth.<ref>{{cite web|url=http://textbookofbacteriology.net/themicrobialworld/Tetanus.html|title=Tetanus| vauthors = Todar K |publisher=University of Wisconsin, Madison - Dept. of Bacteriology|work=Lectures in Microbiology|url-status=dead|archive-url=https://web.archive.org/web/20130311070553/http://textbookofbacteriology.net/themicrobialworld/Tetanus.html|archive-date=2013-03-11}}</ref> It is a [[List of common misconceptions|common misconception]] that rust itself is the cause; a related misconception is that a puncture from a rust-free nail is not a risk.<ref>{{Citation |url=https://nytimes.com/2005/02/22/health/the-claim-stepping-on-a-rusty-nail-can-cause-tetanus.html |title=The Claim: Stepping on a Rusty Nail Can Cause Tetanus | vauthors = O'Connor A |date=February 22, 2005 |newspaper=[[The New York Times]] }}</ref><ref name="Jennings2013">{{cite book|vauthors = Jennings K|title=Because I Said So!: The Truth Behind the Myths, Tales, and Warnings Every Generation Passes Down to Its Kids|url=https://books.google.com/books?id=udIPAQAAQBAJ&pg=PA13|date=2013-10-08|publisher=Simon and Schuster|isbn=978-1-4767-0696-2|pages=13–}}</ref>