Chronic West Nile virus infection in kea (Nestor notabilis)

- Six kea in human care developed acute WNV encephalitis in Austria in 2008.
- One kea died in the acute phase, while five survived 13-72 months.
- WNV RNA was detected in the brains of the persistently infected kea after death.
- The complete WNV genome sequences from the affected birds were determined.
- Phylogenetic analysis of the genomes revealed evolution of WNV in the brains.

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.

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