Rickettsia Flashcards
What causes rocky mountain spotted feiver?
Rickettsia ricketsii
What are the clinical presentations of RMSF
High fever
Severe HA
Macular rash on extremities that evolves to flat discoloration -> petechial rash
How long is the incubation period for RMSF?
Up to 2 weeks
What is the vector for transmission for RMSF?
Prolonged contact with Ticks- transovarian transmission between ticks as well
How is RMSF diagnosed?
Clinical sx, epidemiology + MIF positive results
How is RMSF treated?
Tetracycline, fluoroquinolones
Can you use chloramphenicol for RMSF?
Not recommended due to higher relapse rate
What happens if treatment of RMSF is delayed or untreated?
Delayed treatment: increased chance of death
10-25% mortaliity if untreated
Is there a vaccine for RMSF?
No
What causes Rickettsialpox?
Rickettsia Akari
What is the clinical presentation of Rickettsialpox?
Mild disease with vesicular rash
What is phase 1 of rickettsialpox?
Firm red papule at bite site -> becomes vesicle-> then black eschar as bacteria spreads
What is phase 2 of rickettsialpox?
@9-14 days
High fever, severe HA, chills/sweat,s myalgias, photophobia, vesicular rash
Self limiting after 1 week
What is the transmission vector for rickettsialpox?
Bloodsucking mites
Is rickettsial pox lethal?
No, it is self limiting after 1 week
What causes epidemic typhus?
Rickettsia Prowazekii
What is the clinical presentation of Epidemic Typhus?
Fever, HA, myalgia 1-2 weeks after exposure
Maculopapular rash -> first trunk then spreads to extremities
Which demographic of patients is epidemic typhus more fatal in?
> 40 patients; older
How is epidemic typhus transmitted?
Lice - present in their feces
Gets in when host scratches and breaks into skin
How is epidemic typhus diagnosed?
MIF positive test
How is epidemic typhus treated?
Tetracycline or chloramphenicol
Is there a vaccine for epidemic typhus?
Yes for high risk population
What is Brill-Zinsser?
Relapse of louse borne typhus - appears 10-40 years after first attack
Milder and less fatal
What is the primary reservoir for R.Prowazekii?
Humans
What causes murine typhus?
Rickettsia Typhi
What is the clinical presentation of murine typhus?
Abrupt fever, severe HA, chills, nause, myalgia
LATE maculopapular rash on trunk
What are the transmission vectors for murine typhus?
Flea
What is used to treat murine typhus?
Tetracycline
Doxycycline
Chloramphenicol
