Peste Des Petits Ruminants (PPR)

Peste Des Petits Ruminants (PPR) also known as Goat plague, Pneumoenteritis and KATA in animals.

Peste Des Petits Ruminants (PPR) is an acute or subacute contagious viral disease of goats and sheep characterized by fever, necrotic stomatitis, gastroenteritis, bronchopneumonia and death.

This disease was first described in 1942 in West Africa and it is closely related to rinderpest virus, canine distemper virus and human measles virus.

Etiology

• Peste Des Petits Ruminants (PPR) is caused by peste des petites ruminant disease virus , genus morbillivirus belongs to family paramyxoviridae.
• It is a negative sense single stranded enveloped RNA virus. The envelope contain two type of glycoprotein namely attachment protein and fusion protein. The attachment protein may be either a haemagglutinin and neurominidase protein or a protein without neuraminidase activity. The attachment proteins allow the virus to bind the cell surface receptor and the fusion protein causes the envelope to fuse with host cell membrane for replication.
• The virus is labile in the environment and susceptible to lipid solvents, non-ionic detergent and disinfectants.

Epidemiology

• Distribution: Worldwide.
• The disease is endemic in Indian subcontinent.
• The case fatality rate is higher in goats (55-85%) than in sheep (<10%).
• Kids over 4 months and under 1 yr of age group are highly susceptible.

Transmission

• Close contact with infected animals.
• Inhalation of fine infective droplets  from an infected animal through coughing and sneezing.
•  Ingestion of contaminated feed and water by using of common feed and water trough.

Pathogenesis

• Similar to Rinderpest in cattle.

Clinical manifestation

• It occur as acute and subacute form.
• Incubation period is 4-5 days.

Acute form

• Fever (104-106°F) is accompanied by dullness, sneezing and serous discharge from eyes and nostrils, later it becomes mucopurulent.
• Congested mucous membrane.
• Some animals shows profuse catarrhal conjunctivitis  with matting of eyelids.
• Discrete necrotic lesions develop in the mouth and extend over the entire oral mucosa, forming diphtheritic plaques (necrotic stomatitis).
• Diarrhoea  is profuse, mucoid or blood tinged.
• Bronchopneumonia is characterized by coughing may develop at later stage of infection.
• Abortion may occur in pregnant animal.
• A common feature in later stages of the disease is the formation of small nodular lesions in the skin on the outside of the lips around the muzzle (Orf like lesion).

Subacute form

• It is more common in sheep, but they also occur in goats. The symptoms and lesions are less marked.

Necropsy findings

• Hemorrhagic ulceration is marked in the ileocaecal region, colon and rectum where they produce typical zebra stripes.
• Intracytoplasmic eosinophilic inclusion bodies in intestinal crypt epithelium.
• Intracytoplasmic and intranuclear inclusion bodies in large syncytial giant cells.

Sample collection

• Live animal-Whole blood during febrile stage, oculonasal swab, diphtheritic lesion, faecal sample and paired sera sample.
• Dead animal- Lung, intestine, messentric lymph node.

Diagnosis

• Based on clinical signs and necropsy findings.
• Isolation and identification of virus in cell culture.
• Detection of antibody in serum by  CIE, SNT and ELISA.
• Detection of antigen by  CIE and RT-PCR.

Differential diagnosis

• Pneumonic pasteurellosis
• Contagious caprine pleuropneumonia
• Coccidiosis
• Contagious ecthyma
• Nairobi sheep disease

Treatment

• Antibiotics to control secondary bacterial infections.
• Replacement fluid therapy for dehydration.
• Nasal and mouth lesions are cleaned with mild antiseptics.

Prevention and Control

• Vaccination of kids and lambs over 4 months of age with live attenuated PPR vaccine and annual revaccination every year.
• Ring vaccination of kids and lambs over 4 months of age around 8 km radius from the infected premises to prevent further spread of infection, apart from this Prophylactic measures can be adopted in high risk population. 
• The vaccine is safe, potent and acceptable for use even during pregnancy.
• Segregation of recently purchased animals from unknown sources or sheep and goats that had been sent to shandy but returned unsold.
• Restriction of shared grazing with nomadic or migratory flocks.
• Cleaning and disinfection with 2% sodium hypochlorite.