Bovine Ephemeral Fever (Three Day Sickness)

An economical important disease

1. Bovine Ephemeral FEVER : What you need to know and What you need to do? Dr. Muhammad Avais, DVM, PhD Associate Professor Department of Veterinary Medicine University of Veterinary & Animal Sciences, Lahore

2. Synonyms of BEF T hree-day sickness or three-day fever Bovine influenza Bovine epizootic fever Dengue of cattle Three-day stiffsickness Vernacular name Vil ( Akakpo 2015)

3. What is BEF? Acute febrile viral disease N oncontagious arthropod borne Affects cattle and buffalo widespread in tropical and semitropical areas cause severe economic loss affected animals are only sick for a few days alternative name - Three Day Sickness ( Momtaz et al. 2012; oie 2016)

4. Why BEF is important? l argely economic in nature does not cause significant mortality (1-2%) h igh case fatality rate in recent outbreaks main impact is on productivity decreased milk yield ( at least 50 %) rise in somatic cell count loss of condition reproductive losses (abortion, infertility) Recovery is p rolonged Culling Trade restrictions ( oie 2016)

5. Who causes BEF? Bovine ephemeral fever virus member of genus Ephemerovirus family Rhabdoviridae exist as a single serotype worldwide VN tests on isolates from Australia, China, Japan, Kenya, Nigeria and South Africa have demonstrated strong antigenic cross-reactions (Walker and Klement , 2015; Constables et al. 2017 )

6. vaccines developed in several countries using BEFV strains isolated more than 40 years ago remain effective against currently circulating strains vaccines developed against a strain of the virus from one region are effective against viruses currently circulating in other regions of the world homologous neutralisation titres are typically higher than heterologous titres Walker and Klement , 2015 Who causes BEF?

7. Temporal and phylogenetic relationships between bovine ephemeral fever outbreaks of Asian countries (Lee, 2019)

8. Species affected with BEF Cattle and yaks (both mem . of genus Bos ) Water buffaloes ( Bubalus bubalis ) Antibodies found in sheep, goat and wild animals All age groups susceptible Calves <3-6m not affected Bulls & High producing cows at greater risk no evidence of humans infections ( oie , 2016)

9. Geographic distribution Tropical and subtropical areas of: Africa Asia Middle East Australia BEFV is not found in: Europe North or South America New Zealand (Walker and Klement , 2015) Countries in which BEF is known to occur or from which the disease has been reported historically

10. Morbidity and Mortality localized or seasonal epizootics spread influenced by prevailing winds mostly seen in summer and early fall outbreaks associated with high rainfall morbidity variable (80 % or 1-10%) varies with age, condition and immunity mortality rate is 1-2% in most outbreaks b ut can be 20-30 % in cattle ( oie , 2016)

11. How BEFV is transmitted? Arthropods / hematophagus insects BEFV isolated from mosquitoes and Culicoides Mosquitoes primary biological vectors Culicoides significant vectors in Africa ( Keynya ) Wind-borne carriage of infected vector Intravenous inoculation of small amounts of blood ( oie , 2016)

12. How BEFV is transmitted? No transmission between animals Not transmitted by Close contact body secretions aerosol droplets Not transmitted in semen Rapidly inactivated in meat no evidence of animal becomes carrier ( oie , 2016)

13. How BEF Develops? virus inoculation by vector (mosquitoes) Vascular System ( Virus Multiplication ) Pyrogen and neutrophils influx in bulk (Fever) Vasculitis and thrombosis Increased endothelial permeability Synovial cavities (Sero-fibrinous inflammation) Generalized Inflammation

14. Pathogenesis of BEF

15. Clinical Signs IP; most cases b/t 2-4d, Max. 10-11d signs vary in individual animals classic course begins with fever ( biphasic to polyphasic ) Sharp fall in milk production depressed , stiff or reluctant to move increased heart rate, tachypnea serous or mucoid nasal discharges Profuse salivation, muscle twitching waves of shivering or lacrimation

16. Clinical Signs Shifting lameness, stiffness and joint pain joints may or may not be swollen submandibular or periorbital edema Dyspnea, pulmonary emphysema and rales in severe cases Recombancy Bloat, ruminal stasis, or lose swallowing reflex Temporary lose reflexes /unable to rise Exacerbate by environmental stress or forced exercise Video

17. Causes of death Aspiration pneumonia & Pneumonia from secondary infection Pulmonary emphysema Muscle damaged and inflammation from long period lying down

18. Complications temporary or permanent paralysis gait impairment aspiration pneumonia Pulmonary and subcut Emphysema mastitis Temporary infertility in bulls (up to 6 months) abortions in pregnant cows In recovered animals, milk production is generally decreased for the rest of the lactation but usually returns to normal after subsequent pregnancies Cows that become ill late in lactation may not return to production

19. Postmortem lesions S mall amounts of fibrin-rich fluid in : pleural , peritoneal, pericardial cavities joint capsules Serofibrinous : Polysynovitis , polyarthritis polytendinitis and cellulitis Emphysematous lungs Enlarged edematous lymph nodes Focal necrosis in major muscle groups

20. How to diagnose BEF? Clinical usually diagnosed clinically during outbreaks in endemic areas This disease should be suspected in cattle herds that develop severe but transient symptoms including fever, lameness, temporary paralysis or recumbency Difficult to diagnose when a single animal is affected

21. How to diagnose BEF? Hematology/Biochemistry absolute rise in leukocyte in acute cases A rapid fall in circulating lymphocytes A return to normal levels after 3-4 days Low total serum calcium , Zn and Fe Plasma fibrinogen elevated CK elevated

22. How to diagnose BEF? Laboratory tests Most cases of BEF are confirmed by serology A rising titer should be demonstrated with ELISA -- Paired samples CFT can also be used RT-PCR

23. Differential Diagnosis Foot-and-mouth disease Traumatic pericarditis/reticuloperitonitis: Milk fever Pneumonia/ Pasteurellosis Laminitis

24. CONTROL MEASURES Vaccination   All animals on the farms above 6-months of age may be primed using live attenuated BEF vaccine at the start of summer Make sure vaccine is not expired and the storage and handling requirements are strictly adhered Booster dose of vaccine 4 weeks post-priming Annual booster of vaccine

25. (II) Vector Control BEF virus spreads through biting flies, mosquitoes Fly repellents such as Cypermethrin mixed with liquid paraffin Apply on Pouron method from head to tail. Repeat after every 7 days Spray of Seguvon / Neguvon @ 0.1% on breeding places of vectors (floors, walls, manure, slurry, etc ) Remove stagnant water from the dairy farm Proper disposal of manure / slurry CONTROL MEASURES

26. Control of Ticks Weekly spray of cypermethrin on farm Application of lime on dry floors Filling of crevices (Breeding sites) on floors / walls, etc Elimination of wooden structures on floors CONTROL MEASURES

27. Monitoring and control for blood parasites Animals are often having subclinical form of blood parasites that may be the prime cause of vaccination failure Monitor the herd for hemoparasites through random selected samples If a herd or particular group of cows is positive for blood parasites, treat as per nature of the disease. CONTROL MEASURES

28. III. Movement restriction Movement of cattle from infected herd or area should be strictly banned during the outbreak/epidemic Avoid new purchases and introduction of new animals into the herd. (if necessary, put all new purchases to strict quarantine) CONTROL MEASURES

29. IV. Herd Monitoring Feed and water consumption and production should be carefully monitored at all times Typical sounds and behaviors of individual animals should be monitored Temperature of randomly selected animals should be monitored CONTROL MEASURES

30. V. Biosecurity Strictly adhere to all farm biosecurity measures Do not allow visitors during the outbreak Restrict the entry of service personals and vendors Disinfect farm and farm premises using disinfectants (Virkon or 2% pyodine or 5% Bleach) CONTROL MEASURES

31. TREATMENT STRATEGY (I) Therapeutics Early detection of the clinically sick cases through continuous monitoring Administration of NSAIDs Immune boosters such as Vitamin E and Selenium Calcium therapy ( calcium borogluconate / Milfone -C, I/V) Antibiotics to control secondary bacterial infection like Ceftiofur sodium Cold water therapy to lower body temperature Follow single needle use policy when treating or vaccinating the cows.

32. (II) Nutrition and Environmental Management Increase level of calcium, selenium, vitamin C and vitamin E Reduce stock Density Avoid overcrowding Disease normally followed rainy season due to hot humid climate TREATMENT STRATEGY

33. (III) Isolation of sick cows Keep the infected/diseases animals in isolation and don’t allow them to mix with healthy ones TREATMENT STRATEGY

34. (IV) Management of recumbent cows Nursing care- Animals that have gone down should be provided with adequate shelter, water and food , as cattle left exposed in hot weather are much more likely to die BEF can impair the swallowing reflex, so affected animals should not be drenched or force fed Recumbent cows are rolled over several times a day to help avoid loss of circulation to the underside limbs, which will result in permanent muscle damage. TREATMENT STRATEGY

35. Ensure that animal is in sternal position :  Cattle that go into lateral recombancy (lying flat) can bloat and die or aspirate rumen fluid which can cause pneumonia Place sand bags, hay bales to prop up animals that cannot remain sternal without assistance Calcium injections- if given early in the course of the illness, can be very effective in helping an animal regain its footing . TREATMENT STRATEGY

36. Disinfection BEFV is not thought to be transmitted directly between animals, and does not persist for long periods in the environment If disinfection is needed, this virus is reported to be very susceptible to disinfectants, including sodium hypochlorite, and lipid solvents TREATMENT STRATEGY

37. Summary BEF also know as three-day-sickness Noncontagious arthropod borne viral disease caused by BEFV of genus ephemerovirus Affects cattle and water buffalo Economically important due to reduced milk yield, loss of condition, infertility, trade restriction Transmitted by mosquitoes and biting flies Prevalence in tropical and subtropical areas High morbidity during outbreaks and high case fatality rate

38. BEFV causes vasculitis and increases vascular permeability Polyserositis and polyarthritis Clinical signs are fever, shifting lameness, stiffness, joint pain and recombancy Pulmonary emphysema is the complication Diagnosis by clinical picture, serology and PCR Control through vaccination, vector control and farm hygiene Treat with NSAIDs, immune-boosters and calcium Summary