Horses and People Magazine

The following information, provided by the DPI is a situation breakdown of the Hendra Virus containment at Redlands.

1. On 7 July 2008, a veterinarian advised the Chief Veterinary Officer Queensland of unusual neurological cases in horses at his practice. The veterinarian was of the opinion the equine herpes virus was involved and sought advice on the matter.

2. A total of four horses were reported as being affected over a three week period from late June 2008. One of the horses (Case 3) had been euthanased over the weekend of 5-6 July.

3. Biosecurity Queensland veterinarians attended the practice and secured all available samples, including post mortem samples (Case 1 & 3) and blood from Case 4. The blood samples from Case 3 and 4 were submitted for testing for exclusion of equine herpes virus and Hendra virus on 7 July 2008.

4. Due to the unusual nature of the disease situation, the clinic was quarantine under the Stock Act 1915 on 7 July 2008.

5. At 16.30pm on 8 July 2008, Queensland Health confirmed two positive PCR results for Hendra virus for Cases 3 and 4. In addition, serology on Case 2 was reported as Hendra positive. Samples have been dispatched to AAHL.

6. The case presumptively believed to be the index case was a long term resident of the hospital. It had deteriorated quickly after initially displaying ataxia and then rapidly progressing to being unable to be handled. The horse died on or about 26 June 2008. A brain sample and CSF fluid were taken at the time. The horse was a thoroughbred show horse. (Case 1)

7. The second case was a thoroughbred horse hospitalised for an eye ulcer. Approximately one week into the treatment, it developed mild neurological symptoms that developed further, before the horse recovered. Blood samples were taken from this horse. (Case 2)

8. The third case was a pony hospitalised and treated for a nasal fungal tumour. It was hospitalised for three weeks prior to developing neurological signs. The horse deteriorated and was euthanased on 5 July 2008. A full set of samples is available for this horse (Case 3).

9. The fourth case was an Australian Stockhorse hospitalised for a bilateral jaw fracture. The horse become ataxic on 7 July and deteriorated rapidly. It was euthansed on 8 July 2008 after becoming unmanageable (and subsequent to positive PCR result). Samples are available from this horse, including fresh lung samples. (Case 4)

10. The presenting symptoms in affected horses included ataxia, head tilt, facial nerve paralysis in addition to increased temperatures and purple mucous membranes.

11. There are 37 horses on site at the veterinary practice. All these horses will be tested today 8 July (blood and nasal swabs).

12. Decontamination procedures are underway at the practice under supervision of Biosecurity Queensland.

13. Queensland Health has visited the practice and sampled all persons considered at risk of exposure. Follow up samples will be secured in 14 days time. Counselling has also been provided.

CONSIDERATIONS/ISSUES

14. This is an unusual presentation of Hendra virus, with neurological symptoms the main presentation.
15. Hendra virus was not the initial differential diagnosis in any of the four cases.

16. There are no known bat colonies in the immediate vicinity of the practice.

17. Full epidemiological investigation and tracing of all horses is currently underway.

18. There is considerable media interest in this outbreak. Emphasis is being given that this is not equine influenza, not as infectious and broader industry implications are not expected.

19. It is expected that the practice will remain in quarantine for at least 2 weeks.

20. Further updates will be provided as more results or significant epidemiological information come to hand.

21. Consideration is being given what additional support may be required for the practice as a consequence of the quarantine period.

22. Consideration needs to be given to the future disposition of the recovered horse. Following the 1994 outbreak recovered horses were euthanased owing to the risk of relapse. Biosecurity Queensland has established an expert group to review current scientific knowledge in this regard.

23. Text of updated information sheets for the public and vets is attached. These will be posted on the DPI&F website.