Theileriosis

Synonyms
Etiology
Bovine Theileriosis
life cycle
pathogenesis
clinical findings
diagnosis
treatment
prevention and control

1. Theileriosis Dr. Dhaval F. Chaudhary ( B.V.Sc . & A.H.) College of Veterinary Science & Animal Husbandry, AAU, Anand

2. Synonyms East c oast fever Red water Rhodesian tick fever

3. E tiology Theileriosis is caused by theileria spp . eg ., Theileria parva , Theileria annulata , Theileria ovis . I n cattle, goats, sheep and wild and captive ungulates . Theileriosis is a hemoparasitic disease caused by protozoa of the genus theileria . Theileria species affect domestic and wild ruminants, especially in Africa, Europe, Australia, and Asia. The parasites are transmitted by tick . These parasites, undergo repeated merogony in the lymphocytes ultimately releasing small merozoites , which invade the red cells to become piroplasms . Theileriosis, have a variety of tick vectors which cause infections ranged from clinically inapparent to rapidly fatal .

4. Bovine Theileriosis Bovine theileriosis is caused T. parva . The tick vector is Rhipicephalus appendiculatus . in East Africa . East coast fever generally occur in cattle but also buffalo and occurs ECF is prevalent throughout the water area . T . parva is a highly fatal disease in cattle and this disease is a great threat on the development of the livestock industry, with losses of about 10,000 cattle per year in Zambia.

5. Life cycle of THEILERIA PARVA

6. Pathogenesis Transmitted through bite of ticks of genus Hyalomma . Transmitted mechanically by inoculation of blood and tissue suspension made from spleen, lymph nodes and liver of infected animals. After entry the organism at sporozoit stage remains in blood circulation and enters in erythrocytes but they don’t multiply. Multiplication occurs in lymphocytes where it forms schizonts .

7. Multiplication occurs in lymphocytes where it forms schizonts . Infected lymphocytes are ruptured and schizonts are released and other lymphocytes are affected. Later some schizonts are differentiated unto merozoites . Rapidly multiplying schizonts are causing severe damage to lymphoid cells through their lysis.

8. Clinical Finding High rise of temperature (104F-106F) Enlargment of regional superficial lymph node. Increse heart and respiratory rate. Tense eye balls along with watery lacrimation. Labourrd respiration, serous nasal discharge and coughing. Depression and petechial haemorrhages on counjuctiva . Anemia Bilirubinuria and jaundice in some case. Occasional nervous signs.

9. Diagnosis Demonstration of protozoan parasite in blood smear lymph node biopsy Symptoms and lesions Immunodiagnostic tests for demonstration of antigen /antibody ELISA

10. Treatment Buparvaquone is the most effective drug and the recommended dose in cattle, sheep and goat is 2.5mg /kg BW . Broad spectrum antibiotics like tetracycline, oxytetracycline , chlortetracycline have been used with success. Halofuginone lactate @ 1.2 mg/kg b.wt orally about recovery Bereline has been used with success.

11. PREVENTION AND CONTROL

12. Sanitary prophylaxis Bovine theileriosis is generally controlled by the use of acaricides to kill ticks, but this method is not sustainable. Acaricides are expensive, they cause environmental damage, and over time ticks develop resistance to them requiring newer acaricides to be developed. More sustainable and reliable methods for the control of theileriosis that deploy a combination of strategic tick control and vaccination are desirable, however, these are yet to be successfully applied on a large scale in endemic areas. Sanitation and disinfection measures are not generally effective in preventing transmission of theileriosis.

13. Medical prophylaxis Chemotherapeutic agents such as buparvaquone are available to treat T. parva and T. annulata infections . Treatments with these agents do not completely eradicate theilerial infections and lead to the development of carrier states in their hosts. Recovery from one strain of T. annulata confers cross-protection against most other strains. Complete cross-protection does not occur with T. parva Inactivated vaccines.

14. None are available Live attenuated vaccines. Reliable vaccines of known efficacy have been developed for T. parva and T. annulata . For T. annulata , the vaccine is prepared from schizont -infected cell lines that have been isolated from cattle and attenuated during in-vitro culture . The vaccine must remain frozen until shortly before administration

15. Thank you!!!