Babesia Flashcards
What are the key factors surrounding canine babesiosis?
- Babesia canis is the most common in europe
- It is transmitted by the Dermacentor reticulatus tick
- Most cases occur in the spring and autumn
- The geographical distribution is exapnding in europe
What is babesia?
a blood-borne apicomplexan parasite that invades RBC’s in mammalian hosts
What is the ‘uncomplicated’ pathogenesis of canine babesiosis?
- Invasion of RBCs → parasite multiplication → damage of membrane → haemolysis
- Anti-RBC membrane antibodies → cytotoxic destruction of RBCs
What is the ‘complicated’ pathogenesis of canine babesiosis?
- Cytokine-mediated inflammation
- Tissue hypoxia affecting CNS, kidneys & muscles
What are the clinical signs of canine babesiosis?
Acute babesiosis (inc. period 1-3 weeks) – fever, lethargy, jaundice, vomiting,
anorexia, anaemia
Chronic babesiosis – e.g. depression, intermittent fever, anaemia, myositis, arthritis
unless its subclinical then its asymptomatic
How infectious is bovine babesiosis?
over half the worlds cattle is at risk of infection
What is bovine babesiosis?
A sporadic tick-borne disease in the UK, causes infrequent outbreaks
When do bovine babesiosis outbreaks usually occur?
The outbreaks generally occur in the spring, summer and autumn
What does the epidemiology of bovine babesiosis depend on?
- Parasite species
- Age
- Stress
- Immunity
What are the clinical signs of B.divergens (redwater fever)
- It is usually first reported in may/ june
- has an incubation period of 2 weeks
- Fever
- Diarrhoea
- Red urine
- increased pulse
- abortion
- death
Simply explain the babesia lifecycle
- Parasite found on ticks
- Ticks bite a cow, it enters the bloodstream
- They reproduce, producing merozoites
- RBC’s burst
- when a new tick bites they enter the tick and undergo sexual reproduction in the ticks gut
- Formation of sporozoites which can then migrate up to teh ticks salivary glands
- re-enter another host when tick bites again
How does transovarial transmission of babesia occur?
babesia parasites can be passed on to the larvae of the female tick if she is infected
What are the two tick species that can transmit bovine babesiosis?
- Ixodes ricinus
- Rhipicephalus
What is the best way to diagnose babesia (all species)
- History/ Clinical findings
- Haematological and biochemical tests
- Blood smears (Giemsa stain)
- PCR
- serology (antibody detection)
What bebesia species can recover without treatment?
if caught early
B. divergens
What are the two parasite species that can cause Bovine theileriosis?
- Theileria parva
- Theileria annulata
What is the name of the tick that transmits Theileria parva?
Rhipicephalus appendiculatus
What is the mortality of Theileria parva?
up to 95%
What are the clinical signs of early east coast fever?
- High and sustained fever
- enlarged lymph nodes
- slight listlessness and decreased appetite
What are the clinical signs of late east coast fever?
- increased respiratory rate
- depression
- anorexia
- death within 3-4 weeks of infection
What is the pathogenesis of East Coast Fever?
- Proliferation of parasitised lymphocytes
- parasitised cells disseminate through the lympho-haemopoietic system
- they invade non-lymphoid tissues
- leukocyte depletion -> lymphoid tissues and blood leukocytes
How can cattle become immune against east coast fever?
- any recovered cattle are solidly protected against the homologous challenge
- targets the schizont stage
- cell-mediated
- CD8+ T lymphocytes
- Strain-specific
How can you diagnose east coast fever?
- Microscopic detection of parasites
- PCR
- detection of antibodies
(antibody detection is either immunofluorescent antibodies or an ELISA with recombinant p85)
What is the main vaccine you can use to treat east coast fever?
Inoculation with live sporozoites and simultaneous treatment with long acting oxytetracycline
What are the two subunit vaccines that are used to treat east coast fever?
- CTL that targets antigens
- p67- major surface protein
What are the two ways we can implement vector control?
- Application of acaricides (dipping or spraying)
- Tick vaccines
What are four determinants of tick attack rate?
- Host density
- Climate
- Management practices
- Latitude
What vector transmits plasmodium?
It is transmitted via mosquitos
What disease does plasmodium cause?
malaria
What plasmodium species infects primates to cause ‘monkey malaria’ ?
Plasmodium knowlesi
What are some of the drivers for the emergence of monkey malaria?
- Deforestation
- Increased diagnosis
- Inhibitory interactions between plasmodium species
What is early east coast fever?
- High and sustained fever
- enlarged lymph nodes
- slight listlessness
What is late east coast fever?
- Increased respiratory rate and respiratory distress
- Depression
- Anorexia Death within 3-4 weeks of infection
What are some of the risk factors for ‘monkey malaria’
- Human to human transmission
- any vector associated with the forest
What are some of the drivers for monkey malaria emergence?
- Deforestation- brings macaques and mosquitos to closer proximity
- people venture into the forest for farming, hunting etc
- change in vector behaviour
