Six kea (Nestor notabilis) in human care, naturally infected with West Nile virus (WNV) lineage 2 in Vienna, Austria, in 2008, developed mild to fatal neurological signs. WNV RNA persisted and the virus evolved in the birds" brains, as demonstrated by (phylo)genetic analyses of the complete viral genomes detected in kea euthanized between 2009 and 2014. WNV antibodies persisted in the birds, too. Chronic WNV infection in the brain might contribute to the circulation of the virus through oral transmission to predatory birds.
Animals Animals, Zoo Austria Bird Diseases/pathology* Bird Diseases/virology* Brain/pathology Brain/virology Chronic Disease Disease Outbreaks Female Genome, Viral/genetics Male Parrots/virology* Phylogeny West Nile Fever/pathology West Nile Fever/veterinary* West Nile Fever/virology West Nile virus/classification West Nile virus/isolation & purification West Nile virus/physiology