Phylogenetic Analysis Supports Horizontal Transmission as a Driving Force of the Spread of Avian Bornaviruses.

Background: Avian bornaviruses are a genetically diverse group of viruses initially discovered in 2008. They are known to infect several avian orders. Bornaviruses of parrots and related species (Psittaciformes) are causative agents of proventricular dilatation disease, a chronic and often fatal neurologic disease widely distributed in captive psittacine populations.