Rickettsia prowazekii: Difference between revisions
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Rickettsia prowazekii
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* Cause of '''epidemic typhus''' |
* Cause of '''epidemic typhus''' |
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==Background== |
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===Life Cycle=== |
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* Adult louse becomes infected when feeding on a rickettsemic patient |
* Adult louse becomes infected when feeding on a rickettsemic patient |
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* The louse poops on another person |
* The louse poops on another person |
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* The person scratches their skin or touches their mucous membrane, innoculating themselves with louse feces |
* The person scratches their skin or touches their mucous membrane, innoculating themselves with louse feces |
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===Epidemiology=== |
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* Carried by the human body louse, ''Pediculus humanus corporis'' |
* Carried by the human body louse, ''Pediculus humanus corporis'' |
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* Previously-infected patients may still have latent infection |
* Previously-infected patients may still have latent infection |
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==Clinical Presentation== |
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* Incubation 1 to 2 weeks |
* Incubation 1 to 2 weeks |
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* High fever, severe headache, myalgia, non-producive cough, delirium |
* High fever, severe headache, myalgia, non-producive cough, delirium |
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* In its severe form, can progress to pulmonary edema, encephalitis, shock, and death |
* In its severe form, can progress to pulmonary edema, encephalitis, shock, and death |
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===Brill-Zinsser disease (BZD)=== |
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* Reactivation or recrudescence of dormant typhus years after the initial infection |
* Reactivation or recrudescence of dormant typhus years after the initial infection |
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* Often in the context of malnutrition, chronic illness, and poor hygeine |
* Often in the context of malnutrition, chronic illness, and poor hygeine |
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* Rash may be evanescent or absent, and resolves faster |
* Rash may be evanescent or absent, and resolves faster |
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==Diagnosis== |
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* Four-fold rise in indirect immunofluorescence assay for IgG |
* Four-fold rise in indirect immunofluorescence assay for IgG |
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* PCR may be useful during acute illness |
* PCR may be useful during acute illness |
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==Management== |
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* Need to treat even without confirmed diagnosis |
* Need to treat even without confirmed diagnosis |
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* Doxycycline 100 mg po bid for 7 to 10 days, until afebrile for 24 to 48 hours |
* Doxycycline 100 mg po bid for 7 to 10 days, until afebrile for 24 to 48 hours |
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Revision as of 18:34, 30 June 2020
- Cause of epidemic typhus
Background
Life Cycle
- Adult louse becomes infected when feeding on a rickettsemic patient
- The louse poops on another person
- The person scratches their skin or touches their mucous membrane, innoculating themselves with louse feces
Epidemiology
- Carried by the human body louse, Pediculus humanus corporis
- Outbreaks are associated with poverty, refugee camps, jails, and cold climate
- The only non-human reservoir is the flying squirrel (Glaucomys volans) in the US
- Previously-infected patients may still have latent infection
Clinical Presentation
- Incubation 1 to 2 weeks
- High fever, severe headache, myalgia, non-producive cough, delirium
- Dull, red rash starting on the trunk and spreading peripherally
- Spares palms and soles
- Rash not always present
- Delirium, hemorrhagic rash
- In its severe form, can progress to pulmonary edema, encephalitis, shock, and death
Brill-Zinsser disease (BZD)
- Reactivation or recrudescence of dormant typhus years after the initial infection
- Often in the context of malnutrition, chronic illness, and poor hygeine
- Rash may be evanescent or absent, and resolves faster
Diagnosis
- Four-fold rise in indirect immunofluorescence assay for IgG
- PCR may be useful during acute illness
Management
- Need to treat even without confirmed diagnosis
- Doxycycline 100 mg po bid for 7 to 10 days, until afebrile for 24 to 48 hours
- Chloramphenicol is the alternative
- Wash clothing to prevent outbreaks
