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A ‘new virus’ in North American kea – Avian bornavirus (ABV)
Jessica Meehan (AZA Kea Red SSP Coordinator; Denver Zoo) and Dr Robert Dahlhausen DVM MS (Veterinary Molecular Diagnostics, Inc; Milford OH; leading researcher on Avian bornavirus)
A ‘new’ virus, Avian bornavirus (ABV) – the cause of Proventricular Dilatation Disease (PDD), has been found in the North American population of kea. PDD has been identified since the 1970s, but only recently was the virus that causes it identified. ABV produces a ganglioneuritis of the central, peripheral, and/or autonomic nervous systems resulting in gastrointestinal and neurologic disease. While PDD is often fatal, disease can range from mild to severe. Many ABV positive individuals remain disease-free their entire lifetime. A specialist team is currently formulating plans to study this in more detail in the kea population, and eventually in other parrot populations in zoos. Although there are a number of kea that have become ill, it seems likely that there are a number that have been carrying this virus for years with no deleterious effects. The virus is likely transmitted vertically through the egg. While direct contact transmission may occur, the virus is not readily transmitted from bird to bird. It is likely that we are only finding it now because we are looking for it (unlike West Nile Virus which sweeps through regions via mosquitoes). Specialists are in the midst of testing and
Photo: Corey Mosen
reviewing records for the population, and this will likely take some time. It appears that it is present in a significant percentage of the kea population in North America. The Species Survival Plan (SSP) is working on several studies pertaining to ABV and how it affects kea in particular, with possible implications for other parrot species as well.
Is Avian bornavirus a threat to kea in New Zealand?
(MPI) don’t allow legal importations of parrots into NZ. However, we are still at risk of it being introduced by illegal smuggling” states Brett. Kate McInnes adds that just because it hasn’t been detected, doesn’t mean it isn’t already here; “We don’t have any active surveillance for it, so our main way of picking it up is via private vets or labs who detect it in their patients and report it to MPI, and via the Massey necropsy contract for our wildlife”. ABV could be devastating for all our native parrots, and Brett maintains that it “...is just one disease that could affect wildlife that we have been spared from, thanks mainly to New Zealand’s geographical isolation. Illegal smuggling of birds and reptiles sadly occurs frequently in New Zealand, and people who do this are putting all of our wildlife, including kea, at significant risk”.
New Zealand wildlife veterinarians Brett Gartrell of Massey University’s Wildbase Hospital and Kate McInnes of Department of Conservation both agree that avian bornavirus, an exotic disease, has as yet not been detected in New Zealand birds. However the virus “was introduced into Australia in the last decade through importation of parrots from overseas and is one of the important reasons the Ministry for Primary Industries
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