Rickettsia: Difference between revisions

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Latest revision as of 14:57, 11 November 2025

Background

A genus of obligate mostly-tick-borne intracellular Gram-negative bacteria

Species	Disease	Vector	Distribution
Typhus Group
Rickettsia prowazekii	epidemic typhus	body louse
Rickettsia typhi	murine/endemic typhus	rat/cat fleas
Spotted Fever Group
Rickettsia rickettsii	Rocky Mountain spotted fever (RMSF)	Dermacentor variabilis ticks	eastern, central, and Pacific coast of US
		Dermacentor andersoni ticks	western US
		Rhipicephalus sanguineus ticks	Mexico and southern US
		Amblyomma cajennense ticks	Central and South America
Rickettsia parkeri	American tick-borne fever	Amblyommma maculatum ticks	southern US
Rickettsia parkeri	American tick-borne fever	Amblyomma triste ticks	Uruguay, Brazil, and Argentina
Rickettsia conorii	Mediterranean spotted fever	Rhipicephalus sanguineus ticks
Rickettsia japonica	Oriental spotter fever
Rickettsia heilongiangensis	Far Eastern spotted fever		eastern Russia, Thailand, and China
Rickettsia africae	African tick bite fever	Amblyomma ticks
Rickettsia slovaca	tick-borne lymphadenopathy (TIBOLA)	Dermacentor marginatus ticks
Transitional Group
Rickettsia akari	rickettsialpox	Liponyssoides sanguineus house mouse mites
Rickettsia australis	North Queensland tick typhus
Rickettsia felis	flea-borne spotted fever
Ancestral Group
Rickettsia bellii
Rickettsia canadensis
Other Rickettsiae
Orientia tsutsugamushi	scrub typhus	chiggers
Ehrlichia species	human monocytotropic ehrlichiosis	Amblyomma americanum and other ticks
Anaplasma species	human granulocytic anaplasmosis	Ixodes scapularis and Ixodes pacificus ticks
Neorickettsia		helminths
Wolbachia		helminths and arthropods

Management

Spotted Fever Group

Doxycycline 100 mg po bid for 7 to 10 days
- Alternatively: tetracycline 2 g/day or chloramphenicol 2 g/d
- Alternatively: ciprofloxacin 750 mg po bid for 5 to 7 days
  - But no good evidence for this
Can use doxycycline safely for these duration in children <8 years, and is strongly indicated for rickettsioses
May use azithromycin or clarithromycin in pregnant women
Avoid TMP-SMX, which appears to worsen severity of disease!

@@ Line 1: / Line 1: @@
 ==Background==
-===Microbiology===
 * A genus of obligate mostly-tick-borne intracellular Gram-negative bacteria
+{| class="wikitable"
-==Typhus Group==
+! Species
-* ''[[R. prowazekii]]'': causes epidemic typhus, transmitted by the body louse
+! Disease
-* ''[[R. typhi]]'': causes murine/endemic typhus, transmitted by rat/cat fleas
+! Vector
+! Distribution
+|-
+! colspan=4 | Typhus Group
+|-
+| [[Rickettsia prowazekii]]|| epidemic typhus || body louse ||
+|-
+| [[Rickettsia typhi]]|| murine/endemic typhus || rat/cat fleas ||
+|-
+! colspan=4 | Spotted Fever Group
+|-
+| rowspan=4 | [[Rickettsia rickettsii]]
+| rowspan=4 | Rocky Mountain spotted fever (RMSF)
+| [[Dermacentor variabilis]] ticks || eastern, central, and Pacific coast of US
+|-
+| [[Dermacentor andersoni]] ticks || western US
+|-
+| [[Rhipicephalus sanguineus]] ticks || Mexico and southern US
+|-
+| [[Amblyomma cajennense]] ticks || Central and South America
+|-
+| rowspan=2 | [[Rickettsia parkeri]]
+| rowspan=2 | American tick-borne fever
+| [[Amblyommma maculatum]] ticks || southern US
+|-
+| [[Amblyomma triste]] ticks || Uruguay, Brazil, and Argentina
+|-
+| [[Rickettsia conorii]]|| Mediterranean spotted fever || [[Rhipicephalus sanguineus]] ticks ||
+|-
+| [[Rickettsia japonica]]|| Oriental spotter fever || ||
+|-
+| [[Rickettsia heilongiangensis]]|| Far Eastern spotted fever || || eastern Russia, Thailand, and China
+|-
+| [[Rickettsia africae]]|| African tick bite fever || [[Amblyomma]] ticks ||
+|-
+| [[Rickettsia slovaca]]|| tick-borne lymphadenopathy (TIBOLA) || [[Dermacentor marginatus]] ticks ||
+|-
+! colspan=4 | Transitional Group
+|-
+| [[Rickettsia akari]]|| rickettsialpox || [[Liponyssoides sanguineus]] house mouse mites ||
+|-
+| [[Rickettsia australis]]|| North Queensland tick typhus || ||
+|-
+| [[Rickettsia felis]]|| flea-borne spotted fever || ||
+|-
+! colspan=4 | Ancestral Group
+|-
+| [[Rickettsia bellii]]|| || ||
+|-
+| [[Rickettsia canadensis]]|| || ||
+|-
+! colspan=4 | Other Rickettsiae
+|-
+| [[Orientia tsutsugamushi]]|| scrub typhus || chiggers ||
+|-
+| ''[[Ehrlichia]]'' species || human monocytotropic ehrlichiosis || [[Amblyomma americanum]] and other ticks ||
+|-
+| [[Anaplasma]] species || human granulocytic anaplasmosis ||  [[Ixodes scapularis]] and [[Ixodes pacificus]] ticks ||
+|-
+| [[Neorickettsia]]|| || helminths ||
+|-
+| [[Wolbachia]]|| || helminths and arthropods ||
+|}
+==Management==
-==Spotted Fever Group==
+===Spotted Fever Group===
-* ''[[R. rickettsii]]'': causes Rocky Mountain spotted fever (RMSF)
-* ''[[R. parkeri]]'': carried by ''A. maculatum'' in the southern US and ''A. triste'' in Uruguay, Brazil, and Argentina
-* ''[[R. conorii]]'': causes boutonneuse fever
-* ''[[R. japonica]]'': causes oriental spotter fever
-* ''[[R. heilongiangensis]]'': causes Far Eastern spotted fever in eastern Russia, Thailand, and China
-* ''[[R. africae]]'': causes African tick bite fever
-* ''[[R. slovaca]]'': causes tick-borne lymphadenopathy (TIBOLA)
-** Transmitted by ''Dermacentor marginatus'' ticks
-==Transitional Group==
-* ''[[R. akari]]'': causes rickettsialpox, transmitted by the house mouse mite, ''Liponyssoides sanguineus''
-* ''[[R. australis]]'': causes North Queensland tick typhus
-* ''[[R. felis]]'': causes flea-borne spotted fever
-===Management===
 * [[Is treated by::Doxycycline]] 100 mg po bid for 7 to 10 days
 ** Alternatively: [[tetracycline]] 2 g/day or [[chloramphenicol]] 2 g/d
@@ Line 31: / Line 79: @@
 * ''Avoid'' [[TMP-SMX]], which appears to ''worsen'' severity of disease!
-== Ancestral Group ==
-* ''[[Rickettsia bellii]]''
-* ''[[Rickettsia canadensis]]''
-== Other Rickettsiae ==
-* ''[[Orientia tsutsugamushi]]'': causes scrub typhus, transmitted by chiggers
-* ''[[Ehrlichia]]'': transmitted by ticks
-* ''[[Anaplasma]]'': transmitted by ticks
-* ''[[Neorickettsia]]'': transmitted by helminths
-* ''[[Wolbachia]]'': transmitted by helminths and arthropods
-{{DISPLAYTITLE:''Rickettsia'' species}}
+{{DISPLAYTITLE:''Rickettsia''}}
 [[Category:Rickettsioses]]