BOVINE EPHEMERAL FEVER OUTBREAK

IN PAKISTAN

• (Three-day sickness, Bovine Epizootic Fever, Three-day stiffsickness,

• Dragon boat disease)

Definition

• a noncontagious epizootic arthropod-borne viral disease

• cattle and water buffaloes

• sudden onset of fever

• depression

• stiffness

• lameness

• rapid recovery

Etiology

• Family RhabdoviridaeGenus Ephemerovirus

Type Species Bovine ephemeral fever virus

Epidemiology

• first described in South Africa in 1906

• tropical, subtropical, and temperate countries in Africa, Asia, and Australia

• Thailand since 1984

• Recent Out Break in

• PAKISTAN- 2014

Transmission

• Insect bite

• not spread from cow to cow

– Culicoides

– Mosquitoes

Clinical Signs (1)

• Depressed• High fever (105-107 F) with biphasic or

triphasic fever• Serous ocular and nasal discharge• Anorexia• Decreased milk production• Weight loss• Stiffness and lameness• More severe in high BW animals

• Severe case

Muscle stiffness

Drag feet when forced to walk

Lying down, with hide limbs outstretched-

to relieve muscle cramp

Lie down for three days

Clinical Signs (2)

• Morbidity may reach to 30%

• Low mortality

• Causes of the death

– Pneumonia from secondary infection

– Muscle damaged and inflammation from long period lying down

– Pregnancy toxemia (fatty liver syndrome)

Clinical Signs (3)

Clinical Signs (4)

• Practically Can also be divided in 5 categories

• Lameness

• GIT

• Nervous

• Respiratory

• Sub Cut Emphysema

Sub Cut Emphysema

• Finger is easily Pressed on Back Line underneath it is trapped Air in sub cut tissues

Gross lesions

• the small amounts of fibrin-rich fluid in the pleural, peritoneal, pericardial cavities and joint capsules

• Lungs emphysema

• The lungs may have patchy edema.

Gross Lesions (2)

• Lymphadenitis

• Enlarged Lymph nodes

• Focal necrosis can be found in major muscle groups in some cases.

• the synovial surfaces of the spine may have fibrin plaques.

Hematology

• an absolute rise in leukocyte numbers • a rapid fall in circulating lymphocytes • a return to normal levels after 3-4 days

• The serum fibrinogen level rises to 3-4 times the normal level and returns to normal 1-2 weeks after recovery.

• The total serum calcium level falls to 1.8 mmol-1 during the febrile phases and returns to normal on recovery.

• This is the biochemical event that causes the reversible early paralysis.

Diagnosis

• Clinical signs

• Sero-conversion: paired serum

– SN test

– ELISA

• Gross lesion

Differential Diagnosis

• Bluetongue

• Babesiosis

• Blackleg

Treatment

• Recovery with no treatment

• In severe cases

– Anti-inflammatory drug: NSAIDs

– Fluid therapy and calcium

– Broad spectrum ABO

Recovery period 3-4 wks.

Prevention and Control

• Vector control

• Vaccine: Attenuated lived virus vaccine (Australia)

BEF out break in Pakistan

• Target Animals:– Imported Cattle (Holstein Friesian)

– Not in Local Animals

– Very few in Cross Bred Animals

• Affected Area:– Mega Dairy Farms of Punjab Province

– Not in Sindh

BEFOut Break

• No. Of Animals Effected • More than 2000 High Lactating Cattle

• Mortalities

– Different in different farms

– More than 400 animals died due to BEF

Cause of Mortalities

• Mortalities were not due to

– secondary bacterial Infection

• Main cause was

– Pulmonary/sub cutaneous emphysema