Rickettsia prowazekii: Difference between revisions
From IDWiki
Rickettsia prowazekii
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
* Cause of '''epidemic typhus''' |
* Cause of '''epidemic typhus''' |
||
= Life Cycle = |
== Life Cycle == |
||
* Adult louse becomes infected when feeding on a rickettsemic patient |
* Adult louse becomes infected when feeding on a rickettsemic patient |
||
| Line 7: | Line 7: | ||
* 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 |
||
= Epidemiology = |
== Epidemiology == |
||
* Carried by the human body louse, ''Pediculus humanus corporis'' |
* Carried by the human body louse, ''Pediculus humanus corporis'' |
||
| Line 14: | Line 14: | ||
* Previously-infected patients may still have latent infection |
* Previously-infected patients may still have latent infection |
||
= Clinical Presentation = |
== Clinical Presentation == |
||
* Incubation 1 to 2 weeks |
* Incubation 1 to 2 weeks |
||
| Line 24: | Line 24: | ||
* 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 |
||
== Brill-Zinsser disease (BZD) == |
=== Brill-Zinsser disease (BZD) === |
||
* Reactivation or recrudescence of dormant typhus years after the initial infection |
* Reactivation or recrudescence of dormant typhus years after the initial infection |
||
| Line 30: | Line 30: | ||
* Rash may be evanescent or absent, and resolves faster |
* Rash may be evanescent or absent, and resolves faster |
||
= Diagnosis = |
== Diagnosis == |
||
* Four-fold rise in indirect immunofluorescence assay for IgG |
* Four-fold rise in indirect immunofluorescence assay for IgG |
||
* PCR may be useful during acute illness |
* PCR may be useful during acute illness |
||
= Management = |
== Management == |
||
* Need to treat even without confirmed diagnosis |
* Need to treat even without confirmed diagnosis |
||
Revision as of 20:13, 15 August 2019
- Cause of epidemic typhus
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
