Confirmation last year of a case of the deadly Hendra virus in a horse near the “horse capital of Australia” resulted in a more than 30-fold increase in vaccinations against the pathogen in the region, it has been reported.
The case, in an unvaccinated mare, was reported near Scone in the Upper Hunter Valley, in New South Wales, in June 2019.
Because a case of the bat-borne virus had never been recorded so far south, and the water troughs and hand-feeding areas used by the horse were not under possible bat-feeding sites, the horse owners had logically assessed the risk of Hendra as low.
However, the visiting veterinarian was concerned and opted to submit a sample for Hendra testing, which came back positive.
Kirsten Williamson and her colleagues, writing in the journal One Health, said the case resulted in an urgent human and animal health response.
It involved biosecurity measures, contact tracing, and promotion of the equine vaccine against the virus.
As part of the response, bat ecologists began observations and sampling from the property and local roosts.
Scone falls within the long-term range of grey-headed flying foxes, which have been seen roosting on the affected property at various times over several decades.
While black flying foxes had been recorded roosting in the Lower Hunter Valley and Singleton since the early 2000s, they were first seen in the Upper Hunter Valley in the months before the case occurred, the authors reported.
Fortunately, no human or additional animal cases of Hendra occurred.
Vaccination uptake increased more than 30-fold in the Scone region in the three months following the case, the study team reported.
Most major stud farms in the Hunter Valley adopted a policy under which they would accept mares only if they were vaccinated against the virus.
The case, they said, prompted a review of Hendra virus resources at local and national levels.
“This event near the ‘horse capital of Australia’, is the southernmost known equine Hendra case,” they said.
“Management of the event was facilitated by interagency collaboration involving human and animal health experts. Ongoing One Health partnerships are essential for successful responses to future zoonotic events.”
They say the case signifies an increase in potential equine and human populations at risk of infection.
The study team comprised individuals from a range of institutions, including the Hunter New England Population Health agency in Newcastle, and Australian National University in Canberra.
Hendra in the Hunter Valley. K.M. Williamson, S. Wheeler, J .Kerr, J. Bennett, P. Freeman, J. Kohlhagen, A.J. Peel, P. Eby, T. Merritt, T. Housen, C. Dalton, D.N. Durrheim, Liam Chirio, Adrienne Dale, Devin Jones, Kirk Silas.
One Health, Volume 10, December 2020, https://doi.org/10.1016/j.onehlt.2020.100162