RIFT VALLEY FEVER Synonyms INFECTIOUS ENZOOTIC HEPATITIS Introduction

RIFT VALLEY FEVER

Synonyms • INFECTIOUS ENZOOTIC HEPATITIS

Introduction • RVF is an acute viral disease, insect-borne, of domestic ruminant and humans. • Characterized clinically by fever and death in lambs and calves. • Abortion in pregnant females. • Necrotic hepatitis.

ETIOLOGY – Phlebovirus. – Bunyaviridae – RNA

• Distribution: q. Africa

• Sources of infections and mode of transmission: q. Insect born. q Mechanical and biological trans. q. Aerosols and skin abrasions …minor way. q. To human: via insects or blood.

Susceptible animals • Lambs and kids • Sheep, cattle • Humans and buffaloes.

Factors influencing susceptibility • Young age. • Seasonal.

E. value • High mortalities. • Zoonotic troubles.

Pathogenesis • Severe viremia for a week. inside hepatocytes leading to acute hepatic insufficiency (hepatocellular jaundice) … due to increasing serum bilirubin. • Proliferation • Disturbance in liver enzymes. • Placentitis and death of fetus and abortion. • Death of the animal.

Liver

Normal bilirubin circulation RES Hb……Bilirubin BVs Bilirubin attached with Albumin c. r i cc ti a p he o r nte E Kidney Urobilinogen No bilirubin Intestine Stercobilinogen With faeces Liver Bilirubin is secreted in bile

Hepatocellular damage RES Hb……Bilirubin Kidney Urobilinogen Bilirubin present BVs Increased amount of Bilirubin attached with Albumin Liver Bilirubin is regurgitated Less bilirubin in the bile Intestine Less Stercobilinogen With faeces

Hemolytic jaundice RES Hb……Bilirubin BVs Increased amount of Bilirubin attached with Albumin c. r i cc ti a p he o r nte Kidney Increase Urobilinogen No bilirubin E Intestine Increased Stercobilinogen With faeces Liver Bilirubin is secreted in bile in Excess amount

Obstructive jaundice RES Hb……Bilirubin BVs Bilirubin attached with Albumin reg urg i Kidney NO Urobilinogen Bilirubin present tat Liver No bile secreted ion . Intestine NO Stercobilinogen in faeces

Clinical symptoms • Lambs: – IP: 12 h, 90 % mort. – Fever 41 -42 – Bloody urine, collapse and death. • Adult sheep: – Ip 1 -3 days, 30% mort. – Fever 41 -42 – Bloody urine and diarrhea. – Bloody stained nasal discharge – abortion

Clinical symptoms cont. , • cattle: – Fever 41 – Diarrhea. – Abortion • Humans: – Ip 2 -7 days – Influenza like symptoms. – Congestions of eyes – Encephalitis, jaundice and blindness.

Diagnosis • Case history • Clinical signs • Viral isolation and identification.

Treatment • There is no specific treatment. • Broad spectrum antibiotics • Anti-inflammatory • Supportive treatment

Prevention and control • Solid immunity after recovery lasts for 3 years. • Live attenuated vaccine

• Rift Valley Fever Attenuated Vaccine INDICATION: Protection of sheep and goat against Rift Valley Fever disease. • CONTRAINDICATION: The vaccine not used for pregnant animals • DOSAGE AND METHOD OF USE: * The content of the vaccine vial dissolved in 100 ml. * Each animal can be vaccinated by 1 ml s/c. * Sheep and goat should be vaccinated at 4 months of age. • REMARKS: * Avoid exposure of the vaccine to direct sunlight and heat. * Clinically ill animals should not be vaccinated. * Do not vaccinate animals during breeding season of mosquitoes. * Animals used for human consumption should not be slaughtered within 21 days after vaccination. • * STORAGE: The vaccine should be stored at – 20°C.