Anaplasma (Anaplasmataceae) Flashcards
What agent causes anaplasmosis?
Gram negative, obligate intracellular bacteria
- Anaplasma phagocytophylum (Canine granulocytic anaplasmosis))
- Anaplasma platys (Canine thrombocytic anaplasmosis)
Where (geographically) is anaplasmosis more commonly seen?
Worldwide, more common than E. canis in some regions such as northern California and southern Oregon
What type of cell(s) does anaplasmosis infect?
Leukocytes and platelets
How is anaplasmosis (A. phagocytophylum) transmitted?
Ticks
- Ixodes spp. (equal opportunity agent)
Which species are infected by canine granulocytic anaplasmosis (A. phagocytophylum)?
Dogs, cats, horses, cows, humans
When is canine granulocytic anaplasmosis (A. phagocytophylum) most commonly seen?
Seasonal
- West: April to July
- Midwest: May to June, October to November
Who is the poster child for canine granulocytic anaplasmosis (A. phagocytophylum)?
Old dogs ( > 6-8 years old)
- > 50 years old in people
- Reactivation with immunosuppression
- Reinfection (milder in mice)
What are the clinical signs in a patient with canine granulocytic anaplasmosis (A. phagocytophylum)
- Nonspecific: fever, lethargy, anorexia
- Musculoskeletal: pain, lameness, limb edema
- Hemolymphatic: splenomegaly, hepatomegaly, lymphadenomegaly (similar to ehrlichiosis)
- Neurologic, cough, dyspnea
- No bleeding
- Chronic disease?
How do you diagnose a patient with suspected canine granulocytic anaplasmosis (A. phagocytophylum)?
Clinical signs +
-
Morulae (similar to E. ewingii, need to culture to differentiate)
- Blood or synovial fluid
-
Serology
- Antibodies 2-5 days post morulae
- 4-fold increase or decrease
- Persists for 8-9 months
- 40% seronegative (convalescence 2-4 weeks later)
- PCR
How do you treat a patient with canine granulocytic anaplasmosis (A. phagocytophylum)?
Same as E. canis
- Doxycycline
- Imidocarb
- Pro: injection and compliance
- For those that don’t get better (refractory)
- Coinfections with Babesia canis
- Parasympathetic stimulation (salivation, death)
- Dogs get better, but organism still in circulation
How do you prevent canine granulocytic anaplasmosis (A. phagocytophylum)?
Similar to E. canis
- Absolute tick control (Advantix, Frontline)
- Low dose tetracycline in endemic areas (in food)
Is canine granulocytic anaplasmosis (A. phagocytophylum) zoonotic?
Yes, Human Granulocytic Anaplasmosis
- May occur from direct blood contact
- Vague signs: fever, headache, muscle pain, lethargy
- Half of symptomatic patients require hospitalization
- Mortality < 1%
- Same vector as Lyme
How is canine thrombocytic anaplasmosis (A. platys) transmitted?
Ticks
- Rhipicephalus sanguineus/ Brown Dog Tick?
What are the clinical signs in patient with canine thrombocytic anaplasmosis (A. platys)?
-
Cyclic thrombocytopenia *
- Crisis: ~1 week
- 1-2 week intervals
- Fever, hematochezia (blood through anus), superficial bleeding, anterior uveitis, weight loss
How do you diagnose a patient with suspected canine thrombocytic anaplasmosis (A. platys)?
- Organism in platelets
- Serology? Dot-ELISA
- PCR
