Bovine Ephemeral Fever: Clinical Signs, Transmission, and Epidemiology

1. بسم الله الرحمن الرحيم

2. Department of Pathology Faculty of veterinary medicine

3. BOVINE EPHEMERAL FEVER • By • Dr. SHEREIN SAIED Assistant professor,Pathology DPT.

4. (Three-day sickness, Bovine Epizootic Fever, Three-day stiff sickness),

5. BOVINE EPHEMERAL FEVER • *The name ephemeral fever was applied very early in the disease’s recorded history. • *The disease is not ephemeral in the sense of being hard to see.

6. Three-day sickness • As clinical signs generally persist for about three days then disappear suddenly with complete recovery– • hence the name of the disease

7. Bovine Epizootic Fever • The disease is known to be the same as • Bovine epizootic fever of japan.

8. Three-day stiff sickness, • The disease is • characterized by muscle stiffness

9. (Definition)

10. Definition • -Anoncontagious epizootic • arthropod-born viral disease. • -Affectcattle and waterbuffaloes. • -Characterized by;Sudden • onset offever,depression, • stiffness,lameness, and • rapid recovery.

11. (Etiology)

12. Etiology • Family:Rhabdoviridae Genus:Ephemerovirus Type Species:Bovineephemeral fever virus

14. (Host Range)

15. Cattle and Water Buffaloes

16. Host Range • *All age groups of cattle are susceptible but the disease is more common in age group of 6-24 months. • *Inapparent infections may occur in some wild ruminants. • *Sheep, goats, and other animals are not known to become infected

17. (Epidemiology)

18. Epidemiology • *The disease was first recorded inEast • Africain 1867. *BEF occursenzooticallyin African countriesincluding Egypt,in most of Asia, Middle Eastcountries, Australia and Japan . • *It doesnotoccur in Europe or the • Americas .

19. BOVINE EPHEMERAL FEVER In Egypt

20. In Egypt, • *BEF was first described in 1895 & 1924. • *subsequent outbreaks have been occurred in summer of • 1991,2000,2001 and 2004.

21. * In summer 1991, • a typical form of the disease.has been recorded in different governorates in lower Egypt.

22. *A second outbreak of BEF occurred in summer 2000, whereas it included several governorate in • lower and upper Egypt. • and characterized by • 50% morbidity and • 2.5% mortality.

23. (Transmission)

24. Transmission • *In nature,Only by Insect bite Culicoid-Mosquitoes. *The disease will not spread from cow to cow by; close contact,droplet infection,bodily excretions,or by the transfer or injection of exudates.

25. Transmission • *There is experimental evidence that BEF virus is not spread by semen. *Meat does not represent even a theoretical risk for transmission because the virus is rapidly inactivated at pH levels below 5 (7). Such acidic levels are attained rapidly in bovine muscle after death.

26. Incubation period

27. Incubation period *The incubation period following experimental intravenous inoculation of BEF virus varies between 2 and 4 days, and 9 days is the rare extreme. *The time is probably influenced by; the strain and dose used. *The natural incubation period can only be inferred but is probably similar.

28. Clinical Signs

29. Clinical SignsMild cases

30. *Fever(40-41.5C (105-107 F) with biphasicor triphasic fever spaced 12-18 hrs.)

31. *Discharge from the eyes

32. *Discharge from the nose

33. *Muscle tremor

34. *Temporary lameness.

35. Clinical SignsModerate cases

36. *Animals lying down,

37. *Subcutaneous oedema.

38. *Joint swelling,

39. *Loss of appetite,

40. *Depression,

41. *Loss of rumen motility

42. Clinical SignsSevere case

43. *Muscle stiffness

44. *Drag feet when forced to walk

45. *Lying down(3days),with hind limbsoutstretched-to relieve muscle cramp

46. *Paralysis of limbs.

47. *May lead to coma and death

48. Morbidity and Mortality • *Morbidity • may reach to 30% • *Mortality • Low

49. Causes of the death • i)Pneumoniafrom secondary infection

50. Causes of the death ii)Muscle damaged and inflammationfrom long period lying down