Rickettsia akari: Difference between revisions

From IDWiki
Rickettsia akari
mNo edit summary
No edit summary
Line 1: Line 1:
* Causes '''rickettsialpox'''
* Causes '''rickettsialpox'''


= Microbiology =
== Microbiology ==


* Disease caused by ''Rickettsia akari'', an intracellular Gram-negative bacterium
* Disease caused by ''Rickettsia akari'', an intracellular Gram-negative bacterium
* Unlike most rickettsiae, it has a plasmid
* Unlike most rickettsiae, it has a plasmid


= Epidemiology =
== Epidemiology ==


* Transmitted by the house mouse mite (''Liponyssoides sanguineus'')
* Transmitted by the house mouse mite (''Liponyssoides sanguineus'')
Line 14: Line 14:
* Homelessness and IV drug use are risk factors
* Homelessness and IV drug use are risk factors


= Clinical Presentation =
== Clinical Presentation ==


* Incubation period of 7 to 14 days
* Incubation period of 7 to 14 days
Line 26: Line 26:
* May find leukocytosis
* May find leukocytosis


= Diagnosis =
== Diagnosis ==


* Detection of a four-fold rise in convalescent titres by complement fixation or indirect fluorescent antibodies
* Detection of a four-fold rise in convalescent titres by complement fixation or indirect fluorescent antibodies


= Management =
== Management ==


* Usually self-limited, resolving in 7 to 10 days, though antibiotics help
* Usually self-limited, resolving in 7 to 10 days, though antibiotics help

Revision as of 20:14, 15 August 2019

  • Causes rickettsialpox

Microbiology

  • Disease caused by Rickettsia akari, an intracellular Gram-negative bacterium
  • Unlike most rickettsiae, it has a plasmid

Epidemiology

  • Transmitted by the house mouse mite (Liponyssoides sanguineus)
    • Rodents are the reservoir
  • Most cases are in New York, but it is found worldwide
  • Most likely rickettsiosis to be found in Ontario
  • Homelessness and IV drug use are risk factors

Clinical Presentation

  • Incubation period of 7 to 14 days
  • Present with fever, vesicular rash, and eschar
    • Headache also common
  • The eschar is painless, and appears as a papule about a week after innoculation, followed by vesicle that dries and leaves a brown or black eschar
  • The rash is vesicular, but may be papulovesicular or any other type of rash
    • Lesions leaves black crust and heal without scarring
    • Spares palms and soles
    • Resolves in two to three weeks
  • May find leukocytosis

Diagnosis

  • Detection of a four-fold rise in convalescent titres by complement fixation or indirect fluorescent antibodies

Management

  • Usually self-limited, resolving in 7 to 10 days, though antibiotics help
  • Doxycycline 100 mg po bid for 2 to 5 days and 48 h after fever resolves