Parrot Bornavirus-4 (PaBV-4)

Parrot Bornavirus-4 (PaBV-4)
Why in News?
Scientists from the Assam Veterinary and Fishery University have, for the first time in India, identified and genetically characterised Parrot Bornavirus-4 (PaBV-4), a virus responsible for Proventricular Dilatation Disease (PDD) in captive parrots and other psittacine birds.
Parrot Bornavirus-4 (PaBV-4)
•    PaBV-4 is an avian bornavirus that primarily infects psittacine (parrot) birds.
•    It causes Proventricular Dilatation Disease (PDD), a largely fatal viral disease affecting the digestive and nervous systems.
•    The virus can remain asymptomatic, allowing apparently healthy birds to spread the infection.
•    Genetic analysis confirmed that the virus detected in India belongs to PaBV-4, a strain previously reported in Canada, Israel, Japan, South Korea and the United States.
Key Findings of the Study
•    Researchers tested 83 captive psittacine birds belonging to 13 species from aviaries in Assam, Karnataka and West Bengal.
•    These species included African grey parrot, ochre-marked parakeet, yellow-collared macaw, eastern rosella, blue-crowned hanging parrot, rainbow lorikeet, and scarlet-chested parrot.
•    Out of this, 44 birds tested positive for PaBV-4 infection.
•    Infection was detected in:
o    Nearly 88% of dead birds suspected of PDD.
o    About 19% of apparently healthy cage mates, indicating silent transmission.
•    The infected birds belonged to nine species, including several classified as Near Threatened or Endangered.
Conservation Significance
•    The findings highlight the risk posed by global trade and captive breeding of exotic parrots in spreading infectious diseases.
•    The virus poses a potential threat to the conservation of threatened parrot species as well as the health of captive pet birds.
•    The study underscores the need for disease surveillance, quarantine and biosecurity in aviculture and conservation breeding programmes.
Psittacine Birds
•    Psittacine birds belong to the Order: Psittaciformes.
•    They are characterised by:
o    Strong, curved beaks.
o    Brightly coloured plumage.
o    High intelligence and vocal abilities.
•    The order comprises more than 360 species distributed mainly across the tropical and subtropical regions of the world.
Major Members
•    Parrots
•    Parakeets (including budgerigars)
•    Macaws
•    Cockatoos
•    Cockatiels
•    Lovebirds
•    Lorikeets
•    Rosellas
Distribution
•    Psittaciformes are primarily found in the tropics and southern temperate regions.
•    They occur across South America, Africa, Asia, Australia, New Guinea, New Zealand, Madagascar, the Pacific Islands and the West Indies.
•    In India, they are distributed across much of the country but are largely absent beyond the Himalayan region.