Editing Rickettsia (section)

==Classification==
The classification of ''Rickettsia'' into three groups (spotted fever, typhus, and [[scrub typhus]]) was initially based on [[serology]]. This grouping has since been confirmed by [[DNA sequencing]].  All three of these groups include human [[pathogen]]s. The scrub typhus group has been reclassified as a related new genus,  ''[[Orientia]]'', but they still are in the order Rickettsiales and accordingly still are grouped with the rest of the rickettsial diseases.{{citation needed|date=April 2022}}

Rickettsias are more widespread than previously believed and are known to be associated with [[arthropod]]s, [[leech]]es, and [[protist]]s. Divisions have also been identified in the spotted fever group and this group should probably be divided into two [[clade]]s.<ref name="Gillespie2007">{{cite journal | vauthors = Gillespie JJ, Beier MS, Rahman MS, Ammerman NC, Shallom JM, Purkayastha A, Sobral BS, Azad AF | display-authors = 6 | title = Plasmids and rickettsial evolution: insight from Rickettsia felis | journal = PLOS ONE | volume = 2 | issue = 3 | pages = e266 | date = March 2007 | pmid = 17342200 | pmc = 1800911 | doi = 10.1371/journal.pone.0000266 | bibcode = 2007PLoSO...2..266G | doi-access = free }} {{open access}}.</ref> Arthropod-inhabiting rickettsiae are generally associated with reproductive manipulation (such as [[parthenogenesis]]) to persist in host lineage.<ref name="Perlman2006"/>

In March 2010, Swedish researchers reported a case of [[bacterial meningitis]] in a woman caused by ''[[Rickettsia helvetica]]'' previously thought to be harmless.<ref>[https://www.cdc.gov/eid/content/16/3/490.htm "Rickettsia helvetica in Patient with Meningitis, Sweden, 2006" ''Emerging Infectious Diseases'', Volume 16, Number 3 – March 2010]</ref>

===Spotted fever group===
:* ''[[Rickettsia rickettsii]]'' (Western Hemisphere)
:: [[Rocky Mountain spotted fever]]

:* ''[[Rickettsia akari]]'' (USA, former Soviet Union)
:: [[Rickettsialpox]]

:* ''[[Rickettsia conorii]]'' (Mediterranean countries, Africa, Southwest Asia, India)
:: [[Boutonneuse fever]]

:* ''[[Rickettsia sibirica]]'' (Siberia, Mongolia, northern China)
:: [[North Asian tick typhus|Siberian tick typhus or North Asian tick typhus]]

:* ''[[Rickettsia australis]]'' (Australia)
:: [[Australian tick typhus]]

:* ''[[Rickettsia felis]]'' (North and South America, Southern Europe, Australia)
:: [[Flea-borne spotted fever]]

:* ''[[Rickettsia japonica]]'' (Japan)
:: [[Oriental spotted fever]]

:* ''[[Rickettsia africae]]'' (South Africa)
:: [[African tick bite fever]]

:* ''[[Rickettsia hoogstraalii]]'' (Croatia, Spain and Georgia USA)<ref>Duh, D., V. Punda-Polic, T. Avsic-Zupanc, D. Bouyer, D.H. Walker, V.L. Popov, M. Jelovsek, M. Gracner, T. Trilar, N. Bradaric, T.J. Kurtti and J. Strus. (2010) Rickettsia hoogstraalii sp. nov., isolated from hard- and soft-bodied ticks. ''International Journal of Systematic and Evolutionary Microbiology'', 60, 977–984; [https://archive.today/20120710185809/http://ijs.sgmjournals.org/cgi/content/abstract/60/4/977], accessed 16 July 2010.</ref>
:: Unknown pathogenicity

===Typhus group===
:* ''[[Rickettsia prowazekii]]'' (worldwide)
:: [[Epidemic typhus]], recrudescent typhus, and sporadic typhus

:* ''[[Rickettsia typhi]]'' (worldwide)
:: [[Murine typhus]] (endemic typhus)

===Scrub typhus group===

:* The causative agent of [[scrub typhus]] formerly known as ''R. tsutsugamushi'' has been reclassified into the genus ''[[Orientia]]''.{{Rickettsialesphylogeny}}