11 - rickettsiosis, ehrlichiosis, anaplasmosis, neorickettsiosis Flashcards
1
Q
(Rocky Mountain Spotted Fever)
- caused by what?
A
- Rickettsia rickettsiae
2
Q
(Rocky Mountain Spotted Fever)
- most common where in USA?
A
- southeast, midwest
3
Q
(Rocky Mountain Spotted Fever)
- transmitted by what ticks?
- what is the reservoir?
- most infections April-oct
A
- American Dog Tick (Dermacentor variablis)
wood tick (dermacentor andersoni)
- rodents
4
Q
(Rocky Mountain Spotted Fever)
- bitten by tick -> organism invades what?
resulting in what?
- high mortality?
A
- vascular endothelial cells
necrotizing vascultisi, edema, dmg of organs
- yep
5
Q
(Rocky Mountain Spotted Fever)
- common cx?
- thrombocytopenia is common, as is leukocytosis with a left shit, anemia, and toxic granulation of neutrophils
A
- fever, joint pain, ocular signs, neuro signs, petechial hemorrhages
6
Q
(Rocky Mountain Spotted Fever)
(dx)
- confirmed by what?
- IFA is dx under what two conditions?
A
- serum antibody titers and PCR
- single high titer, or four-fold increase in paired serum samples
7
Q
(Rocky Mountain Spotted Fever)
(tx)
- drug of choice?
A
- doxycycline (good prog if given early)
8
Q
(canine ehrlichiosis)
- caused by a variety of species of Ehlichia. canis, ewingii, chaffeensis.
- what tick transmits E. canis? geo?
- E. ewingii? geo?
- E. chaffeensis?
A
- brown dog tick (Rhipecephalus sanguineous) southeast
- lone-star tick (amblyomma americanum) southern and central US
- lone-star tick; south
9
Q
(canine ehrlichiosis)
- E. canis and E. chaffeensis infect what?
- E. ewingii?
A
- monocytes and phagocytes
- granulocytes
10
Q
(canine ehrlichiosis)
- acute signs of infection occur a few weeks after tick bite and last 2 to 4 weeks - what are they?
A
- fever, anorexia, lethargy, oculonasal discharge, lymphadenopathy, splenomegaly, hepatomegaly, thrombocytopenia
(e. ewingii commonly causes polyarthritis)
11
Q
(canine ehrlichiosis)
- after acute phase, a long subclinical phase follows and can last form months to years.
A
12
Q
(canine ehrlichiosis)
(dx)
- serology with IFA is reliable - may not see titers until 2 to 4 weeks after infection
A
13
Q
(canine ehrlichiosis)
(dx)
- can see in blood luekocytes, and morulae in bone marrow cells or spirats of LN
- E. canis and chaffeensis are found where?
E. ewingii?
A
- monocytes
neutrophils
14
Q
(canine ehrlichiosis)
- tx with what?
A
- doxycycline
15
Q
(anaplasmosis)
- caused by what?
- transmitted by what ticks?
- reservoir?
- see where in US?
A
- anaplasma phagocytophilum
- ixodes
- mouse
- NE, upper midwest, pacific coast of california