Editing Syphilis (section)

==Cause==
===Bacteriology===
{{Main|Treponema pallidum{{!}}''Treponema pallidum''}}
[[File:Treponema pallidum 01.png|thumb|upright=1.4|[[Histopathology]] of ''Treponema pallidum'' bacteria using a modified [[Silver stain|Steiner silver stain]], 1986|alt=]]

''Treponema pallidum'' subspecies ''pallidum'' is a spiral-shaped, [[Gram-negative]], highly mobile bacterium.<ref name=Music08/><ref name=Pri2008/> Two other human diseases are caused by related ''Treponema pallidum'' subspecies, [[yaws]] (subspecies ''pertenue'')  and [[nonvenereal endemic syphilis|bejel]] (subspecies ''endemicum''), and one further caused by the very closely related  ''Treponema carateum'', [[Pinta (disease)|pinta]].<ref name=Kent08/><ref>{{cite journal |vauthors=Giacani L, Lukehart SA |title=The endemic treponematoses |journal=Clinical Microbiology Reviews |volume=27 |issue=1 |pages=89–115 |date=January 2014 |pmid=24396138 |pmc=3910905 |doi=10.1128/CMR.00070-13}}</ref> Unlike subspecies ''pallidum'', they do not cause neurological disease.<ref name=Wood09/> Humans are the only known [[natural reservoir]] for subspecies ''pallidum''.<ref name=ST10>{{Cite journal |last1=Stamm |first1=LV |title=Global challenge of antibiotic-resistant ''Treponema pallidum'' |journal=Antimicrobial Agents and Chemotherapy|date=February 2010|volume=54|issue=2|pages=583–89|pmid=19805553|doi=10.1128/aac.01095-09|pmc=2812177}}</ref> It is unable to survive more than a few days without a [[Host (biology)|host]].<ref name=Pri2008/> This is due to its small genome (1.14[[base pair|Mbp]]) failing to encode the metabolic pathways necessary to make most of its macronutrients.<ref name=Pri2008/> It has a slow [[doubling time]] of greater than 30&nbsp;hours.<ref name=Pri2008/> The bacterium is known for its ability to evade the immune system and its invasiveness.<ref>{{Cite journal |last1=Peeling |first1=RW |last2=Mabey |first2=D |last3=Kamb |first3=ML |last4=Chen |first4=XS |last5=Radolf |first5=JD |last6=Benzaken |first6=AS |title=Syphilis. |journal=Nature Reviews. Disease Primers |date=12 October 2017 |volume=3 |pages=17073 |doi=10.1038/nrdp.2017.73 |pmid=29022569 |pmc=5809176 }}</ref>

===Transmission===
Syphilis is transmitted primarily by sexual contact or during [[pregnancy]] from a mother to her baby; the bacterium is able to pass through intact mucous membranes or compromised skin.<ref name=Kent08/><ref name=ST10/> It is thus transmissible by [[kissing]] near a lesion, as well as [[Non-penetrative sex#Manual sex|manual]], [[Oral sex|oral]], [[Vaginal sex|vaginal]], and [[anal sex]].<ref name=Kent08/><ref name=CDC2004/><ref>{{cite book| last1 = Hoyle | first1 = Alice | last2 = McGeeney | first2 = Ester |title=Great Relationships and Sex Education|publisher=Taylor and Francis|year=2019|access-date=11 July 2023|isbn=978-1-35118-825-8|url=https://books.google.com/books?id=KE7ADwAAQBAJ&pg=PT261}}</ref> Approximately 30% to 60% of those exposed to primary or secondary syphilis will get the disease.<ref name=Eye07>{{cite journal |author=Bhatti MT |title=Optic neuropathy from viruses and spirochetes |journal=Int Ophthalmol Clin |volume=47 |issue=4 |pages=37–66, ix |year=2007 |pmid=18049280 |doi=10.1097/IIO.0b013e318157202d |s2cid=2011299 }}</ref> Its [[infectivity]] is exemplified by the fact that an individual [[Inoculation|inoculated]] with only 57 organisms has a 50% chance of being infected.<ref name=Pri2008/> Most new cases in the United States (60%) occur in men who have sex with men; and in this population 20% of syphilis cases were due to oral sex alone.<ref name=Kent08/><ref name="CDC2004">{{cite web |title=Transmission of Primary and Secondary Syphilis by Oral Sex --- Chicago, Illinois, 1998–2002 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5341a2.htm |website=Morbidity and Mortality Weekly Report |publisher=[[Centers for Disease Control and Prevention|CDC]] |language=en |date=21 October 2004 |access-date=15 January 2019 |archive-date=5 August 2020 |archive-url=https://web.archive.org/web/20200805010501/https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5341a2.htm |url-status=live }}</ref> Syphilis can be transmitted by [[blood product]]s, but the risk is low due to screening of [[Blood donation|donated blood]] in many countries.<ref name=Kent08/> The risk of transmission from [[sharing needles]] appears to be limited.<ref name=Kent08/>

It is not generally possible to contract syphilis through toilet seats, daily activities, hot tubs, or sharing eating utensils or clothing.<ref name=CDC2014>{{cite web |title= Syphilis & MSM (Men Who Have Sex With Men) - CDC Fact Sheet |publisher= [[Centers for Disease Control and Prevention]] (CDC) |date= 16 September 2010 |url= http://m.cdc.gov/en/HealthSafetyTopics/DiseasesConditions/STDs/syphilisMSM_FS |access-date= 18 October 2014 |url-status= dead |archive-url= https://web.archive.org/web/20141024093624/http://m.cdc.gov/en/HealthSafetyTopics/DiseasesConditions/STDs/syphilisMSM_FS |archive-date= 24 October 2014}}</ref> This is mainly because the bacteria die very quickly outside of the body, making transmission by [[fomite|objects]] extremely difficult.<ref name="Csonka1990">{{cite book|author=G. W. Csonka|title=Sexually transmitted diseases: a textbook of genitourinary medicine|url=https://books.google.com/books?id=o6NrAAAAMAAJ|year=1990|publisher=Baillière Tindall|isbn=978-0-7020-1258-7|page=232|url-status=live|archive-url=https://web.archive.org/web/20160503035653/https://books.google.com/books?id=o6NrAAAAMAAJ|archive-date=3 May 2016}}</ref>