Babesia Flashcards
Where is babesia found?
Intra-erythrocytic
What are the species of babesia in UK and how are they transmitted?
*B. divergens - transmitted by Ixodes ricinus
*B. major - transmitted by Haemophysalis punctata
What are the species of babesia found in the tropics and how are they transmitted?
*B. bovis + B. bigemina - transmitted by Rhipicephalus spp
What is babesia’s life cycle?
1.Merozoites divide by asexual binary fission in RBCs
2. Ticks ingest infected RBCs - multiplication + sexual repro in the tick
3.Dissemination of babesia throughout the tissues into the ovaries
4. infection passed to new host by next generation of ticks - attach => sporogony occurs in salivary glands
5.Sporozoites inject into host with tick saliva => enters RBCs and divide (merogony)
What are the clinical signs of babesia?
2 weeks after infection
*high temp (fever)
*haemoglobinuria
*haemolytic anaemia
*diarrhoea for 36hours then becomes constipation
What is the epidemiology of babesia
*Seen May => November - ticks active, herds on pasture, endemic in west Britain
*inverse resistance = calves <9months = resistant to disease but not infection
What is Endemic stability?
*host, infection, vector and environment coexist with absence of disease
*expose young stock to infection = no disease
*outbreak if - buying in naive animals, introduce partial tick control,
re-seeding pasture, removing ticks
How would you diagnose babesia?
*clinical signs
*history of exposure
*season
*PCR
*stained blood smears - identification of merozoites in RBCs
How is babesia treated?
*Imidocarb - protection from clinical disease for up to 4 weeks
- allows sufficient infection for immunity
- withdrawal = 21 days milk, 213days meat
*blood transfusion for very anaemic animals
What are other tick-borne diseases?
*Theileria spp - cattle in tropics (east coast fever)
*Anaplasma spp - infect range of ruminants
*Enhrlichia ruminantum (heartwater)
What stain picks up the merozoites in the RBCs?
Giemsa stain
