Hendra virus update

The first Hendra case in a horse for 2012 has been confirmed by Biosecurity Queensland after samples collected on 4 January were tested positive.

There were 23 confirmed cases of Hendra virus infection in horses in Queensland (thirteen cases on ten properties) and New South Wales (ten cases on eight properties) during 2011.

One dog on one of the Queensland properties tested positive although it showed no signs of disease. More about Hendra and dogs

Each of the sixteen incidents in 2011 were attributed to different groups of flying foxes and the infections are not being spread from property to property.

All infected properties are out of quarantine.

Hendra facts page

Footage of a horse suffering from Hendra virus

New South Wales

A tenth horse in NSW was confirmed dead from Hendra virus on 30 August at a property near Ballina.

On 17 August it was confirmed that a sixth horse in NSW has died from Hendra virus at a property near Ballina, and on 18 August three more horses were reported as confirmed Hendra cases - two on a new property near Ballina, and one on a new property at Mullumbimby.

A Hendra case in a horse was confirmed near Wollongbar in New South Wales on Friday 1 July. The companion horse on this property subsequently showed clinical signs, was euthanased and confirmed as a Hendra case on 13 July.

A second NSW property had a confirmed case that was reported on 7 July in Macksville on the mid-north coast. This is the southernmost case that has been reported.

A third incident of Hendra virus infection in a horse was confirmed on 16 July on a property near Lismore and a fifth horse died from Hendra virus at a property near Mullumbimby on 27 July.

Queensland

The most recent case of Hendra virus was reported on 5 January in the Townsville area. The three year old horse was first noticed to be unwell on the morning of Tuesday 3 January 2012. A private vterinarian examined the horse on Tuesday 3 January and collected samples which tested positive. Biosecurity Queensland has quarantined the property and is working with the horse owner in conjunction with other government agencies.

The last case of Hendra virus was reported in a horse on 15 October at Beachmere just north of Brisbane, following the first case on the same property that was confiremd positive on 11 October.

On 26 July Queensland’s Chief Veterinary Officer confirmed that a dog tested positive for Hendra virus infection on a Mount Alford property, 100km south-west of Brisbane. This is the first time outside laboratory conditions that Hendra virus infection has been found in an animal other than a horse, a flying fox or a human.

The dog, which was on a property where with Hendra virus infection was found in horses, was routinely tested as part of the quarantine process. The dog returned two negative results for the presence of the virus, but a different test conducted at the Australian Animal Health Laboratory (Geelong), has confirmed the presence of antibodies. The dog was subsequently euthanased to minimise the risk of the virus re-emerging later and infecting people or other animals.

More about Hendra and dogs

There have been ten horse Hendra incidents in Queensland this year. The second most recent case was confirmed on 23 August at a property in the Gold Coast hinterland. Two cases were confirmed on 22 July - one from a horse that died the previous month in Logan, and another from a recent death in Chinchilla. The Chinchilla case is the first confirmed west of the Great Dividing Range. While initial tests were negative for the Logan horse, further testing at the Australian Animal Health Laboratory showed that the horse had been exposed to Hendra virus.

Two unrelated incidents were confirmed on 16 July on properties at Hervey Bay and Boondall. They each involved one confirmed case of Hendra virus infection in a horse.

The previous case was reported on 12 July from a property at Kuranda west of Cairns and the property is under quarantine. Horse tracing is underway, and 36 horses on the property are being tested.

Biosecurity Queensland confirmed a third case in Park Ridge on the outskirts of Brisbane and quarantined four properties on 5 July. The horse died, and there were no other horses on the property.

A second confirmed Hendra case in a horse was reported by Biosecurity Queensland on Saturday 2 July. The horse was euthanased on Thursday and the tests returned positive to Hendra virus on Friday night. Another horse on the property was ill and died two weeks ago and was confirmed as positive to Hendra virus. Another horse became ill and was euthanased on 4 July. The property is at Mount Alford near Boonah.

The first confirmed case was in a horse near Beaudesert south of Brisbane. The horse died from the disease.

Biosecurity Queensland issued information for horse owners and industry organisations:

Veterinarians have also been circulated with regular information updates:

The most recent guidelines for veterinarians on handling suspected Hendra cases is available from Biosecurity Queensland.

There is plain English information for horse owners and members of the public about Hendra virus on the Biosecurity Queensland and NSW Primary Industries websites.

More about Hendra and dogs

With a family pet testing positive to Hendra virus for the first time, 2011 continues to be an extraordinary year for Hendra virus cases. It's not known how the dog became infected, but it was most likely through close contact with one of the infected horses on the property.

Although the dog showed no signs of illness, it tested positive to antibodies to the Hendra virus, indicating that there had been contact with the virus. This is the first time outside laboratory conditions that Hendra virus infection has been found in an animal other than a horse, a flying fox or a human.

Dogs, cats and other animals that might have had contact with infected horses have been routinely tested for Hendra virus for several years, but none has ever tested positive before. This unusual occurrence will hopefully help scientists understand more about the virus and how it's transmitted.

Hendra virus can re-emerge after being dormant, which may pose a risk to humans and other animals. For this reason, the only safe place for an animal that may have been infected (even if it has recovered) is in a high level biocontainment facility. There would be no contact with any other animal, no access to the open air, and the only contact with humans would be when they were wearing pressurised biosecurity protection suits. This would not be a humane way to care for the animal, so the national policy agreed by state and federal governments is to euthanase animals that recover from a Hendra virus infection.

Two dogs were exposed to Hendra virus in laboratory conditions during the 1990s, and one became infected. While this wasn't a long term study, scientists concluded from their observations that it was unlikely that dogs would become infected under normal conditions.

Advice for dog owners

There has not been a case of Hendra virus in a dog before, although many dogs have been tested on properties where horses have been infected. This is an extremely rare occurrence.
Sick animals, especially horses, should be kept away from all other animals to avoid spreading disease.
Good hygiene is always a good idea around dogs and other animals - it's not a good idea to let dogs lick people's faces at any time, and you should wash your hands after touching any animal.
Children under ten years should always be supervised by an adult around dogs.

Comments

Hendra virus update

Submitted by Dr Peter Reid on 10 August 2011.

The comment in this article that "Hendra virus can re-emerge after being dormant, with the animal shedding virus without warning and posing a deadly risk to humans and other animals" is factually and scientifically incorrect. There is no published research demonstrating that Hendra virus is shed in secretions after lying dormant in the brain and relapsing in a patient, be it either human or animal.

Thanks for the clarification

Submitted by Ms Marcia Balzer on 10 August 2011.

Thanks for the clarification on this detail, Peter. I have amended the text to say 'which may pose a risk to humans and other animals'.

hendra virus

Submitted by Dr Charissa Smith on 08 July 2011.

1. Is this virus possibly mediated by increasing wild pigs, camels, mice or rats? ( see Menangle virus) 2. Is the virus like distemper where the carrier state can manifest in old age eg neurological symptoms, fly snapping in dogs 3. What is the effect of a vaccine on a human or horse which is a chronic carrier? As this virus has been around for years, it is possible that these are out there in the community. 4. Do chronic carriers which are asymptomatic still have titres? How much is known?

Answers to questions

Submitted by Dr Barry Smyth on 18 July 2011.

1. The only known reservoir of Hendra virus in Australia is the flying fox. There is no clinical disease in infected flying foxes. No other companion animal, farm animal, native animal or feral animal has been shown to be a reservoir of this virus. Reasons for the current increase in Hendra cases in 2011 remain under investigation. 2. There is no known carrier state. About 70% of horses will die from the initial infection. If horses recover, the current national policy is to destroy them to prevent any chance of a spillover into humans. All active and passive surveillance testing of horses from around Australia indicates that the only horses detected with Hendra virus infection are those with clinical disease and with a positive test to Hendra virus. There are no characteristic clinical signs for Hendra virus infection in horses. 3. Currently no vaccine is available. Vaccine development is underway to protect horses against acquiring an infection with Hendra virus. We expect this is about 12 to 18 months away from commercial reality. 4. See 2 above.