Rickettsia akari: Difference between revisions

Latest revision as of 14:08, 15 October 2020

Background

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 Manifestations

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

@@ Line 1: / Line 1: @@
+==Background==
 * 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'')
-** Rodents are the reservoir
+**Rodents are the reservoir
-* Most cases are in New York, but it is found worldwide
+*Most cases are in New York, but it is found worldwide
-* Most likely rickettsiosis to be found in Ontario
+*Most likely rickettsiosis to be found in Ontario
-* Homelessness and IV drug use are risk factors
+*Homelessness and IV drug use are risk factors
-= Clinical Presentation =
+==Clinical Manifestations==
-* Incubation period of 7 to 14 days
+*Incubation period of [[Usual incubation period::7 to 14 days]]
-* Present with fever, vesicular rash, and eschar
+*Present with [[Causes::fever]], [[Causes::vesicular rash]], and [[Causes::eschar]]
-** Headache also common
+**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 [[Causes::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
+*The rash is vesicular, but may be papulovesicular or any other type of rash
-** Lesions leaves black crust and heal without scarring
+**Lesions leaves black crust and heal without scarring
-** Spares palms and soles
+**Spares palms and soles
-** Resolves in two to three weeks
+**Resolves in two to three weeks
-* 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
-* Doxycycline 100 mg po bid for 2 to 5 days and 48 h after fever resolves
+*[[Is treated by::Doxycycline]] 100 mg po bid for 2 to 5 days and 48 h after fever resolves
 {{DISPLAYTITLE:''Rickettsia akari''}}