Parrot Bornavirus 4 (PaBV-4)

About Parrot Bornavirus 4 (PaBV-4)

• Parrot Bornavirus 4 (PaBV-4) is an enveloped single-stranded RNA virus belonging to the genus Orthobornavirus in the family Bornaviridae.
• Target Species: It infects parrots and other psittacine birds such as macaws, cockatoos, parakeets, conures, cockatiels, budgerigars, and lovebirds.
• Discovery by: It was identified and genetically characterised in India by a team from Assam Veterinary and Fishery University.
• Distribution:
  • Global: It has been documented in the U.S., Canada, Israel, Japan, South Korea, and Europe.
  • India: It has been identified in captive birds from Assam, Karnataka, and West Bengal.
• Pathogenesis: It causes a persistent non-cytolytic infection in which immune-driven inflammation damages the digestive and nervous systems, leading to enlargement of the proventriculus, poor digestion, and central nervous system inflammation.
• Transmission:
  • Direct Spread: It spreads through infected birds, contaminated food, water, saliva, feces, droppings, and feather dust.
  • Silent Spread: Healthy-looking infected birds can shed the virus, and infected parents can also pass it to eggs.
• Impacts
  • Bird Health: It causes Proventricular Dilatation Disease (PDD), resulting in weight loss despite normal appetite, regurgitation, undigested seeds in droppings, neurological signs, poor digestion, and eventual death.
  • Conservation: Its high prevalence in global aviculture and spread through the commercial bird trade threaten captive breeding programmes and endangered parrot species.
• Diagnosis: RT-PCR (Reverse Transcription Polymerase Chain Reaction) detects the virus from cloacal swabs in live birds and from brain and proventriculus tissues in dead birds.
• Treatment: There is currently no specific antiviral treatment or vaccine, and management focuses on supportive care, reducing inflammation, and maintaining nutrition.