Rickettsia: Difference between revisions

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Rickettsia
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==Background==
===Microbiology===
* A genus of obligate mostly-tick-borne intracellular Gram-negative bacteria
* A genus of obligate mostly-tick-borne intracellular Gram-negative bacteria


== Typhus Group ==
==Typhus Group==

* ''[[R. prowazekii]]'': causes epidemic typhus, transmitted by the body louse
* ''[[R. prowazekii]]'': causes epidemic typhus, transmitted by the body louse
* ''[[R. typhi]]'': causes murine/endemic typhus, transmitted by rat/cat fleas
* ''[[R. typhi]]'': causes murine/endemic typhus, transmitted by rat/cat fleas


== Spotted Fever Group ==
==Spotted Fever Group==

* ''[[R. rickettsii]]'': causes Rocky Mountain spotted fever (RMSF)
* ''[[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. parkeri]]'': carried by ''A. maculatum'' in the southern US and ''A. triste'' in Uruguay, Brazil, and Argentina
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** Transmitted by ''Dermacentor marginatus'' ticks
** Transmitted by ''Dermacentor marginatus'' ticks


=== Transitional Group ===
==Transitional Group==

* ''[[R. akari]]'': causes rickettsialpox, transmitted by the house mouse mite, ''Liponyssoides sanguineus''
* ''[[R. akari]]'': causes rickettsialpox, transmitted by the house mouse mite, ''Liponyssoides sanguineus''
* ''[[R. australis]]'': causes North Queensland tick typhus
* ''[[R. australis]]'': causes North Queensland tick typhus
* ''[[R. felis]]'': causes flea-borne spotted fever
* ''[[R. felis]]'': causes flea-borne spotted fever


=== Management ===
===Management===

* [[Doxycycline]] 100 mg po bid for 7 to 10 days
* [[Doxycycline]] 100 mg po bid for 7 to 10 days
** Alternatively: tetracycline 2 g/day or chloramphenicol 2 g/d
** Alternatively: tetracycline 2 g/day or chloramphenicol 2 g/d
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== Ancestral Group ==
== Ancestral Group ==

* ''[[Rickettsia bellii]]''
* ''[[Rickettsia bellii]]''
* ''[[Rickettsia canadensis]]''
* ''[[Rickettsia canadensis]]''


== Other Rickettsiae ==
== Other Rickettsiae ==

* ''[[Orientia tsutsugamushi]]'': causes scrub typhus, transmitted by chiggers
* ''[[Orientia tsutsugamushi]]'': causes scrub typhus, transmitted by chiggers
* ''[[Ehrlichia]]'': transmitted by ticks
* ''[[Ehrlichia]]'': transmitted by ticks

Revision as of 18:40, 30 June 2020

Background

Microbiology

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

Typhus Group

  • R. prowazekii: causes epidemic typhus, transmitted by the body louse
  • R. typhi: causes murine/endemic typhus, transmitted by rat/cat fleas

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. conorrii: 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

  • 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 Septra, which appears to worsen severity of disease!

Ancestral Group

Other Rickettsiae