Rickettsia rickettsii - "Rocky mountain spotted fever"

Question 1

transmission of Rickettsiae spp.

Answer 1

dog tick –> transmission after tick bite or contact w/ crushed haemolymph if crushed

*humans are accidental hosts

Question 2

Clinical syndrome of Rickettsiase spp

Answer 2

“Rocky mountain spotted fever”

Question 3

Diagnosis of Rickettsiae spp

Answer 3

obligate intracellur, like gram(-)

test: Microscopy
–> stains Giemsa or Gimenez stain
*stains poor w/ gram

Question 4

Clinical manifestaions of R.ricketsii

Answer 4

TRAID: FEVER + RASH + HEADACHE

1) fever > 39 °C
2) Rash –> petechial rash on soles and palms (characteristic)
3) Headache –> if sever might be ass. w/ meningioencephalitis
4) tick bite eschar ( single dark black lesion)

Question 5

tx of R. rickettsii

Answer 5

Abx reduce mortality from 10-25% –> 3%

Question 6

patho of Rickettsia rickettsii

Answer 6