Infectious Agents in blood Flashcards
1
Q
Cytauxzoon life cycle
A
Tick vector
- tick injects sporozoite
- sporozoite infects monocyte
- shizont fills up macrophage
- shizont bursts and piroplasms infect RBCs
- *Bobcats also serve as reservoir
2
Q
cytauxzoon felis
host, what phase makes cat sick?, reservoirs, risk factors
A
- host: tick
- macrophage phase is what makes cat sick and is the driving force of anemia; replication inside monocyte
- reservoir: wild cats, chronically infected cats
- large range with severity
- risk factor: outdoors, immune status
3
Q
cytauxzoon felis : what does it cause
A
- anemia (non-regenerative) +/- thrombocytopenia +/- leukopenia
-hyperbilirubinemia
+/ increased liver enzymes and abnormal coagulation
4
Q
cytauxzoon felis : presentation
A
- fever
- icterus
- splenomegaly / organomegaly
- dyspenia
- hypothermia
5
Q
cytauxzoon felis : Dx
A
- PCR takes long time
- blood slide is the way to go (look for inclusions and macrophages eating everything)
6
Q
cytauxzoon felis : Tx and prevention
A
- atovaquone + azithromycin
- safe acaracides
- stay indoors
7
Q
babesia in cats
A
NOT IN THE USA
8
Q
babesia large forms (found in USA)
A
- B. Vogeli (mild in adults, severe in puppy)
- B. coco (new and rare)
9
Q
babesia small forms (found in USA)
A
- B. gibsoni (can be severe)
- B. conradae
- B. microti-like
10
Q
babesia :
- breed and infection predispositions
- Dx
A
- large form: from ticks, greyhounds
- small form: from bite, pitt
- Dx from blood slide (venous or ear prick); serology; PCR can tell you genus and species
11
Q
babesia : replication and blood work findings
A
-replicates in RBC
- thrombocytopenia !!
-hemolytic anemia
-marked neutrophilia
- positive coombs is possible (immune activation)
+/- inflammatory leukogram
12
Q
babesia clinical signs
A
-fever
-lethargy
-weakness
-pale MM
-splenomegaly
+/- renal failure and neuro signs (we dont know why)
13
Q
babesia tx
A
- B. vogeli : imidocarb diproprionate
- B. gibsoni: atovaquone and azithromycin
- -> if you’re not sure which you have, pick tx to start and wait for PCR
14
Q
hepatozoon types and what does it look like on slide ?
A
- oval light blue capsule effecting neutrophils
- H. Americanum: dog is off-target host, severe illness, tissue phase causes muscle cysts, low parasitemia (dog eats tick)
- H. Canis: dog is main host, clinically mild, high parasitemia
15
Q
hepatozoon Americanum signs and labs
A
-fever, lethargy, cachexia, lame with muscle pain, mucopulent ocular discharge
-marked neutrophilia, mild to mod non-regenerative anemia
+/- hypoalbuminemia, hyperglobulinemia, increased ALP (due to bone lysis but CK is ok which is weird)
16
Q
hepatozoon Americanum dx and tx
A
- muscle biopsy, blood PCR may be false negative, buffy coat examination lack sensitivity
- H. canis: Imidocarb diproprionate
- H. americanum: trimethoprim-sulfadiazine, clindamycin, primethamine, decoquinate for over 2yrs!
17
Q
mycoplasma : transmission and lab findings
A
- transmission via arthropods, flea
- severity varies
- parasetemia is transient and may be missed in blood smear
- chem may be normal
18
Q
cat mycoplasma types
A
- M. haemofelis: most severe
- M. heamominutum: mild, smaller looking
- M. turicensis: mild, only isolated by PCR and never seen in blood film
19
Q
mycoplasma risk factors
A
-feline: young (<3yr), outdoor, chronically ill, hx of cat bite abscess, male, retroviral +
20
Q
dog mycoplasma types and blood slide appearance
A
- M. haemocanis: unapparent dz unless splenectomized or immunocompromized
- M. hematoparvum
- -> little bacteria look like chains inside RBC
21
Q
mycoplasma tx
A
- tetracyclines, fluroquinolones
- supportive (may add pred)
22
Q
Where to find shizonts (Cytox)
A
feathered edge
liver, spleen
23
Q
What stage causes the disease in cytox?
A
the macrophage (shizont) clogs vessels in major organs.
24
Q
How reliable is PCR for cytox?
A
eh
6% of healthy cats were PCR positive
chronically infected domestic cats are likely a reservoir
25
cytox blood work
Anemia, may cause pancytopenia if bone marrow is affected
Macrophages in liver -> Bilirubinemia, inc. liver enzymes, coagulopathy
26
Cytox. what is it?
protozoan
| pale circle with basophilic rim infecting RBCs and monocytes
27
presentation for cytox
(infected 1-3 wks earlier)
| fever, icterus, splenomegaly, dyspenia, hypothermia
28
Cytox treatment
- Tick preventative
| - Atovaquone & Azithromycin
29
Babesia, what is it?
Protozoal
only in dogs
small form and large form, look like tear drops.
30
Where to find Babesia
just in RBCs!
31
Most common Large form and small form?
| Which causes milk and severe disease?
Large: B. vogeli - mild disease
Small: B. gibsoni (all the small type cause severe disease)
32
Babesia transmission
blood, either thru tick or bite wound
33
Babesia bloodwork
hemolytic anemia
thrombocytopenia
possibly Coombs positive
+/- inflammatory leukogram
34
Babesia clinical signs
```
fever
lethargy, weakness
pale MM
splenomegaly
may have CNS signs
```
35
PCR for babesia?
Gives you genus and species
| - start treating after you diagnose on blood smear, change to more appropriate tx when PCR comes back if necessary
36
Treatment for babesia
vogeli - imidocarb
gibsoni - atovaquone and azithromycin
prednisone if there's a severe secondary IMHA
37
Hepatozoan. what's it look like?
Light blue capsule with purple nucleus (infecting neutrophils)
38
hepatozoan mechanism of infection?
Dog eats tick or eats the muscle with encysted organisms
-> encysts in muscle
- coyote may be preferred species for h. americanum. but dog is preferred host for h. canis
39
contrast H. canis with H. americanum
```
H. canis / H. Americanum
dog / coyote
mild signs / severe illness
multiple organs / muscle cysts
lots in blood / low level parasitemia
```
40
clinical sings H. americanum
| and blood work?
nonspecific - fever, lethargy, lameness, muscle pain
CBC- marked neutrophilia, mild-moderate NONregenerative anemia
Chem- hypoalbuminemia, hyperglobulinemia, inc. ALP (from BONY proliferation)
41
list for marked neutrophlic leukocytosis
```
pyo-everything
IMHA
Neoplasia
Babesia
Hepatozoon
```
42
Diagnosis for h. canis
muscle biopsy is the most sensitive
- PCR of blood is ok but can have false negatives
- buffy coat lacks sensitivity
43
treatment h. canis
succkksss.
| if using decoquinate takes over 2 years. (americanum)
44
mycoplasma on smear
| shipping?
bacteria, multiple on surface of RBCs, look at edges of cell
| - shipping causes them to fall off cell surface
45
mycoplasma - anemia and presentation? transmission?
regenerative or preregenerative mild to moderate anemia
| transmission unknown
46
diagnosis mycoplasma?
transient parasitemia, easily missed on blood smear
Chem - may be normal, hypoxia
use PCR to confirm
47
most severe mycoplasma
M. haemofelis (large form)
48
mild mycoplasma
M. haemonimutum (small form)
49
risk factors for mycoplasma
<3 yrs, outdoor access, clinically ill, history of cat bite abscess, male
50
Canine mycoplasma?
unapparent disease unless immunosuppressed or spenectomized
51
Which Erlichia have round nuclei?
E. canis and E. chanffeensis
52
Ehrlichia
tick borne
| intracellular g- bacteria
53
ehrlichia blood work
thrombocytopenia, mild anemia possible
54
acute and chronic phases of infection of E. canis?
acute - 10-20 days; nonspecific signs
becomes chronic or subclinical
chronic - 40-80 days; bone marrow aplasia, ill, bleeding
55
e. canis bloodwork
thrombocytopenia
possible anemia (esp if chronic)
may have hyperglobulins, lymphocytosis in blood
56
diagnosis ehrlichiosis
snap test available (serologic)
PCR (splenic sample best)
hard to find on smear
57
specific clinical sign for E. ewingii and A. phagocytophilum
lamesness due to neutrophilic polyarthropathy
58
Anaplasma that doesn't affect neutrophils?
A. platys - platelets -> cyclic thrombocytopenia
| usually not evident in blood smear
59
Histoplasma blood work
Regenerative anemia
| inflammatory
60
Rangelia vitalli
Brazil, not in US yet
- bleeding from ears
- genetically simillar to Babesia
- also tick borne
- infects RBC, WBC, endothelial cells
61
Host only cats
```
cytox
mycoplasma (but happens in immunosuppressed/splenectomized dogs)
```
62
Host only dogs
babesia (and rangeli)
Ehrlichia (rare in cats)
Hepatozoan
63
both dogs and cats
histoplasma
64
tickborn parasites
literally all of them except mycoplasma which is unknown transmission and histoplasma
65
infects just RBCs
babesia
| Mycoplasma
66
infects monocytes and RBCs
cytox
67
infects neutrophils
hepatozoan, and then encysts in muscle
68
infects mononuclear cells
Ehrlichia. c
69
Protozoan
cytox
babesia(and rangeli)
hepatozoan
70
bacteria
mycoplasma
| ehrlichia
71
fungus
histoplasma
72
nonregenerative anemia
hepatozoan
73
thrombocytopenia
(cytox if marrow affected)
babesia
ehrlichia
rangeli
