Newcastle Disease Virus

PARAMYXOVIRIDAE

Hosts

• Gallinaceous birds, pigeons, parrots, finches
• Subclinical carriers: ducks, ostriches
• Causes conjunctivitis in humans

Pathogenesis

• Transmission via aerosol and direct contact
• Disease ranges from subclinical respiratory tract infections -> torticollis -> haemorrhages and death

Diagnosis

Two diagnostic tests currently exist:

• Animal test:
  • Samples of trachea and gut of 20 birds are tested in eggs
  • HI using anti-NDV serum (to differentiate HA caused by avian influenza
  • Virulence of isolate tested by the speed it kills chicks
• DNA test (which will soon replace the animal test):
  • Sequencing the cleavage site of H gene
  • The more basic amino acids the more virulent the virus

Control

• Newcastle Disease is NOTIFIABLE
• Vaccination of chickens and racing pigeons
• Surveillance of imported exotic birds
• Isolation of infected stock
• Infected premises to be culled and firebreak cull if spread