Rickettsia: Difference between revisions

Revision as of 18:54, 30 June 2020

Background

Microbiology

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

Species	Disease	Vector
Typhus Group
R. prowazekii	epidemic typhus	body louse
R. typhi	murine/endemic typhus	rat/cat fleas
Spotted Fever Group
R. rickettsii	Rocky Mountain spotted fever (RMSF)	Dermacentor variabilis and Dermacentor andersoni ticks
R. parkeri	American tick-borne fever	Amblyommma maculatum (Gulf Coast tick) in the southern US, and Amblyomma triste in Uruguay, Brazil, and Argentina
R. conorrii	Mediterranean spotted fever	Rhipicephalus sanguineus ticks
R. japonica	Oriental spotter fever
R. heilongiangensis	Far Eastern spotted fever in eastern Russia, Thailand, and China
R. africae	African tick bite fever	Amblyomma ticks
R. slovaca	tick-borne lymphadenopathy (TIBOLA)	Dermacentor marginatus ticks
Transitional Group
R. akari	rickettsialpox	Liponyssoides sanguineus house mouse mites
R. australis	North Queensland tick typhus
R. 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 3: / Line 3: @@
 * 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
+|-
-===Spotted Fever Group===
+! colspan=3 | Typhus 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. prowazekii]]'' || epidemic typhus || body louse
+|-
-* ''[[R. japonica]]'': causes oriental spotter fever
+| ''[[R. typhi]]'' || murine/endemic typhus || rat/cat fleas
-* ''[[R. heilongiangensis]]'': causes Far Eastern spotted fever in eastern Russia, Thailand, and China
+|-
-* ''[[R. africae]]'': causes African tick bite fever
+! colspan=3 | Spotted Fever Group
-* ''[[R. slovaca]]'': causes tick-borne lymphadenopathy (TIBOLA)
+|-
-** Transmitted by ''Dermacentor marginatus'' ticks
+| ''[[R. rickettsii]]'' || Rocky Mountain spotted fever (RMSF) || ''[[Dermacentor variabilis]]'' and ''[[Dermacentor andersoni]]'' ticks
+|-
-===Transitional Group===
+| ''[[R. parkeri]]'' || American tick-borne fever || ''[[Amblyommma maculatum]]'' (Gulf Coast tick) in the southern US, and ''[[Amblyomma triste]]'' in Uruguay, Brazil, and Argentina
-* ''[[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
+| ''[[R. conorii]]'' || Mediterranean spotted fever || ''[[Rhipicephalus sanguineus]]'' ticks
+|-
+| ''[[R. japonica]]'' || Oriental spotter fever ||
-=== Ancestral Group ===
+|-
-* ''[[Rickettsia bellii]]''
+| ''[[R. heilongiangensis]]'' || Far Eastern spotted fever in eastern Russia, Thailand, and China ||
-* ''[[Rickettsia canadensis]]''
+|-
+| ''[[R. africae]]'' || African tick bite fever || ''[[Amblyomma]]'' ticks
-===Other Rickettsiae===
+|-
-* ''[[Orientia tsutsugamushi]]'': causes scrub typhus, transmitted by chiggers
+| ''[[R. slovaca]]'' || tick-borne lymphadenopathy (TIBOLA) || ''[[Dermacentor marginatus]]'' ticks
-* ''[[Ehrlichia]]'': transmitted by ticks
+|-
-* ''[[Anaplasma]]'': transmitted by ticks
+! colspan=3 | Transitional Group
-* ''[[Neorickettsia]]'': transmitted by helminths
+|-
-* ''[[Wolbachia]]'': transmitted by helminths and arthropods
+| ''[[R. akari]]'' || rickettsialpox || ''[[Liponyssoides sanguineus]]'' house mouse mites
+|-
+| ''[[R. australis]]'' || North Queensland tick typhus ||
+|-
+| ''[[R. felis]]'' || flea-borne spotted fever ||
+|-
+! colspan=3 | Ancestral Group
+|-
+| ''[[Rickettsia bellii]]'' || ||
+|-
+| ''[[Rickettsia canadensis]]'' || ||
+|-
+! colspan=3 | 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==