Flashcards in Arthropod-bourne infectious disease 1 Deck (59)
What tick borne pathogens my be importe in dogs travelling from EU
NON ENDEMIC to UK: babesia canis canis, babesia gibsoni, ehrlichia canis
ENDEMIC TO UK: borrelia burgdorferi, anaplasma phagocytophilum
Which ticks are present in Europe?
- Ixodes ricin us: widespread
- Dermacentor reticularis: more restricted distribution
- Rhipicephalus sanguineus : life cycle requires temp > 18 degrees, not endemic in UK, intro from dogs travelling from EU, establish in houses / kennels here, vector for Mediterranean spotted fever (rickettsia conorii), carries babesia and ehrlichia
What are babesia and theileria?
Most important agents of canine babesiosis
- LARGE BABESIA: b. Canis canis, B canis vogeli and B. Canis Rossi
- SMALL BABESIA: b. Gibsoni
How do different babesia spp vary?
- geo distribution
- response to tx
Babesia pathogens sis
- within ticks transmitted trans-stadially and trans-ovarially
- sporophytes injected from tick salivary glands
- enter circulation, endocytosed by RBC
- IM component of pathology
- TP common (but usually doesn't cause bleeding or abnormal coagulation)
Which babesia spp are zoonotic?
- b.microti - rodent reservoir
- b. Divergent - cattle reservoir
CS - babesiosis
- those of haemolytic anaemia
- lethargy, depression, inappetance
- tachycardia and tachypnoea
Babesia - diagnosis
1 clinical laboratory findings: non-specific, TP common, many dogs are Coombs positive / auto agglutinate
2. Microscope identification : low sensitivity so must use another test to verify
3. PCR : high sensitivity, broad range babesia PCR, spp id possible using species specific PCR / sequencing
4. Serology: usually IFA or ELISA
Babesia - tx
- antibabesia drug : Imidiocarb dipropronate
- LARGE BABESIA: rapid clinical response
- SMALL FORMS : clinical and parasitological cure uncommon, clinical relapses may occur
What type of bacteria are rickettsia?
Small obligate intracellular gram negative
Which rickettsia infect monocytes?
- ehrlichia canis
- ehrlichia Chaffeensis: causes human monocytes ehrlichiosis, transmitted by ambylomma americanum, molecular evidence canine infections
Which rickettsial parasite infects thrombocytes?
Which ricketssia infects granulocytes?
- anaplasma phagocytophilum
- ehrlichia erwingii
Incubation time - ehrlichia canis
Acute CS - ehrlichia canis
- vascular is and immune destruction leading to thrombocytopenia and cpagulopathy
- multi systemic signs
- spleen and LN enlargement
- CNS / ocular signs
Chronic - CS - ehrlichia canis
- BM destruction leading to pancytopaenia
- signs as for acute
Species infected by ehrlichia canis
Dogs and wild canids only
Diagnosis - ehrlichia canis
- modular in blood smears or macrophages from tissue as pirates (spleen, lung, LN)
- thrombocytopenia / pancytopaenia
Tx/ prevention - Ehrlichia canis
-tx: TCs for 28d/ chloramphenicol
- no vaccine
- chemo prophylaxis
- tick control
Anaplasma phagocytophilum - CS
- mild/ moderate TP
- mild anaemia
- naturL chronic infection has not been seen
- impaired PMn function can predispose to secondary infection
A. Phagocytophilum in cats?
A.phagocytophilum - zoonotic?
Yes but unclear if infected domestic animals pose zoonotic risk. May have role as sentinels
What is Borrelia burgdorferi sensu lato associated with?
Hosts - borrelia
Humans, dogs incidental host (sylvatic tick- wildlife cycle)
What are the Borrelia pathogenic genospecies?
- b.afzelli (skin complications)
- b. Garinii (Neuro complications)
- b.burgdorferi sensu stricto ( the only pathogenic spp in USA, present in some parts of. Europe and can cause Neuro / arthritic complications)
What is the most prevalent tick- transmit infection in temperate areas of Europe, USA and Asia?
Lyme disease in people
CS - human Lyme disease
- erythema migrans in 80-90%
- later involves skin, Neuro and msk systems
Overall mean prevalence of b.burgdorferi in ticks in Europe
12%. Central Europe has highest tick infection rates