ProMED-mail |

Published Date: 2012-07-28 21:31:31
Subject: PRO/AH/EDR> Hendra virus, equine - Australia (09): (QL)
Archive Number: 20120728.1218748

HENDRA VIRUS, EQUINE - AUSTRALIA (09): (QUEENSLAND)
***************************************************
A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org

[1] Hendra case in a horse in Mackay (Official)
[2] Hendra case in a horse in Mackay [Media]
[3] Hendra case in 2 horses in Rockhampton [Media]

[1] Hendra case in a horse in Mackay (Official)

Date: Sat, 28 Jul 2012
Source: News Release, Queelsland Government, Agriculture, Fisheries & Forestry [edited]
http://www.daff.qld.gov.au/30_21856.htm

New Hendra virus case in Mackay
--------------------------------
Biosecurity Queensland is managing a new Hendra virus case near Mackay after a positive test result was received last night [27 Jul 2012]

Queensland Chief Veterinary Officer Dr Rick Symons said the property manager contacted a veterinarian after discovering the horse was gravely ill on Tuesday. After the vet took samples, the horse was euthanased.

"There are a number of other animals including horses on the property and on adjoining properties," Dr Symons said.

"Tracing is a priority to determine what contact the infected horse had with other animals on all properties.

"Biosecurity Queensland officers are on the property this morning and are in the process of quarantining.

"Restrictions will apply to moving horses and horse materials on and off the infected property, and the property will be quarantined for at least one month."

Queensland Health's Public Health experts have assessed the situation and determined only one person has had contact with the infected horse. This person has been assessed as having low-level exposure to the horse. This person wore personal protective equipment and took other appropriate precautions.

Queensland Health's Senior Director Communicable Diseases Dr Christine Selvey reassured the community that transmission of the virus required close contact with body fluids of an infected horse.

"Queensland Health staff will continue to undertake contact tracing work to ensure all people potentially exposed to the infected horse have been identified," Dr Selvey said.

"Queensland Health stands ready to provide any assistance, counselling, information, testing or treatment that may be required.

Dr Symons said this latest case was the 4th Hendra virus incident in Queensland this year. Previous incidents include one in Townsville in January and 2 in May - one in Ingham and one in Rockhampton.

"Testing is continuing on both the Ingham and Rockhampton properties which are still under quarantine," he said.

"Horse owners need to remain vigilant in taking steps to reduce the risk of infection as Hendra virus can occur year round but is more common during the cooler months. If a horse becomes sick, owners should contact their veterinarian immediately as happened in this case."

The latest 'Guidelines for veterinarians handling potential Hendra virus infections in horses' [version 4.2, updated Dec 2011] is available for veterinarians at http://tinyurl.com/bmdozwp.

--
Communicated by:
ProMED-mail <promed@promedmail.org>

******
[2] Hendra case in a horse in Mackay [Media]

Date: Sat, 28 Jul 2012
Source: The Cairns Post [edited]
http://www.cairns.com.au/article/2012/07/28/230565_local-news.html

Horse Hendra death in Far North forces lockdown
-----------------------------------------------------
A Redlynch property is in lockdown after a horse carrying the Hendra virus died yesterday morning.

Biosecurity Queensland placed the Redlynch Equestrian Association grounds in lockdown for 96 hours yesterday [Fri, 27 Jul 2012], after tests confirmed the 4-year-old gelding was carrying the disease.

Association president Kevin Goan said the horse 1st started to give indications it had contracted Hendra on Wed [26 Jul 2012] night, with lockdown protocols initiated straight away that restricted the movement of animals and people.

"It (the horse) was first seen to be ill on Wednesday morning and by Wednesday evening it had developed a fever," Mr Goan said. "He had respiratory distress and showed signs of some neurological disorder in that he was unsteady in his movement."

After being seen by a private veterinarian on Wednesday, the horse tested positive for Hendra yesterday [Friday morning after samples were taken on Thursday.

Mr Goan said none of the 14 horses remaining on the property had shown any Hendra-related symptoms so far, with the association hoping that it was an isolated incident. "We're an association established to provide everyone with the opportunity to pursue their equine interests, and there's a lot of comings and goings from the property which is a little bit alarming to all the membership," Mr Goan said. "The property hosted the dressage competition that was a part of the Cairns Show festivities a fortnight ago, which is within the incubation period of the disease."

No person or animal is permitted to enter or exit the property as a result of the lockdown.

Queensland chief veterinary officer Rick Symons said Biosecurity Queensland was now trying to determine whether any other animals had come in to contact with the deceased horse. "Movement restrictions will apply to horses and horse materials on and off the infected property throughout the quarantine period," Dr Symons said.

Queensland Health public health experts, meanwhile, will visit the property and do contact tracing work within the next few days to determine if any people were exposed to the disease.

[Byline: Michael Serenc]

--
Communicated by:
ProMED-mail <promed@promedmail.org>

******
[3] Hendra case in 2 horses in Rockhampton

Date: Fri, 27 Jul 2012
Source: 9News [edited]
http://news.ninemsn.com.au/article.aspx?id=8506598

2 horses euthanased on Hendra-hit property
------------------------------------------
Two horses at a central Queensland property quarantined because of a Hendra disease outbreak have been euthanased. A foal died of Hendra virus on the hobby farm, near Rockhampton, last week [see 20120720.1208397].

Queensland chief veterinary officer Dr Rick Symons says the horses suddenly became ill and were showing nervous signs. They were put down at the owners' request to prevent further suffering.

"The rapid onset of illness and the clinical signs all suggested Hendra virus infection, which was confirmed by laboratory test results late yesterday," Dr Symons said in a statement on Friday. "There are no more horses on the property, but there are still 2 dogs. They are being monitored daily and the property will remain under quarantine until late August."

The property owner's initial tests for Hendra virus have been returned negative. She suffered a high-level of exposure to the bat-borne virus, which is usually fatal in humans, after nursing the foal before its death.

Three properties near Mackay also remain under quarantine after a confirmed case of Hendra virus last month.

Biosecurity Queensland confirmed on Friday night that it was quarantining a property in the Cairns area after a horse returned an initial positive test for Hendra virus infection.[see item 2 further].

Queensland Chief Veterinary Officer, Dr Rick Symons, said the horse was sick on Wednesday and died on Friday morning.
A number of other horses are known to be on the property, and Biosecurity Queensland is identifying what other animals came into contact with the deceased horse.

"Movement restrictions will apply to horses and horse materials on and off the infected property throughout the quarantine period," Dr Symons said in a statement.

--
Communicated by:
ProMED-mail <promed@promedmail.org>

[The following information, derived from the official Hendra pages of Queelsland's Government Department of Agriculture, Fisheries & Forestry, may be useful to readers.

a. What we know:
----------------

1.Hendra virus has been fully characterised genetically, and its relationship to other known viruses is well understood.
2.The virus' behaviour in various species has become well understood through experimental studies.
3.While the virus can be fatal in horses and humans, it does not spread easily from an infected individual (i.e. it has poor transmissibility).
4.The virus is very fragile and is easily killed by heat, desiccation or disinfection.
5.Species of fruit bats (flying foxes) were identified as a natural reservoir of Hendra virus in just two years, which was a tremendous achievement compared with other emerging diseases, such as Ebola virus, where identifying the reservoir in nature took 30 years.
6.The virus has been detected in the urine, saliva, faeces and birthing fluids of flying foxes.
7.Hendra virus infection in horses is rare considering the number of horses in Queensland (approximately 200,000). There has been 32 spillovers between 1994 and 2011.
8.Horses are the sole species known to be infected from the natural reservoir, though several other domestic species can be infected experimentally when injected with large doses of the virus, including cats, guinea pigs and pigs.
9.The source of infection for a dog that became sub-clinically infected in 2011 is uncertain, but it was more likely exposed to one of the three infected horses on the property than infected from flying foxes.
10.We know in detail how the virus causes disease (its pathogenesis), which body organs are most likely to be affected and how the virus is excreted from infected individuals.
11.Flying foxes show no apparent signs of infection but infection in horses is fatal in about 75 per cent of cases. Infection in humans is fatal in about 50 per cent of cases.
12.The seven human cases have resulted from close contact with an infected horse.
13.Many other people who have had close contact with infected horses have not become infected (again indicating poor transmissibility).
14.There is no evidence that humans can contract Hendra virus from flying foxes.
15.Spillover from flying foxes to horses has occurred only in paddock situations where flying foxes are present in the local area.
16.Hendra virus infection in flying fox colonies is typically episodic and not continuous.
17.Infection in flying foxes and spillover to horses can occur in any month but is more likely to occur between June and September.
18.Some species of flying foxes may be more significant in the maintenance and transmission of Hendra virus.
19.A combination of ecological, horse husbandry and human factors appear to contribute to the risk of spillover.
20.Initial research into an effective vaccine for horses and an effective treatment protocol for humans is promising, and research is ongoing.
21.Currently, the most effective way to minimise the likelihood of Hendra virus infection is to manage contact between horses and flying foxes through practical husbandry measures. 22.Despite the number of equine cases there were no human cases in 2011, suggesting that veterinarians and horse owners are following recommendations on safely managing infected horses.

b. What we don't know:
---------------------

The following important questions still remain:

1.The reason that infection in flying foxes and spillover to horses appear more likely at some times than others is still unknown. This is a key research area, and factors being investigated include ecological changes, physiological and immunological factors.

2.The specific mode of transmission from flying foxes to horses remains uncertain, but the virus is readily recovered from urine under trees in which flying foxes are roosting or feeding, and experimental studies show that horses can be infected by the oral route. QCEID is currently using infrared photography to investigate nocturnal interactions between horses, flying foxes and other nocturnal species.

Subscribers may refer to OIE's Manual chapter 2.9.6. "Hendra and Nipah Virus Diseases" at
http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/2.09.06_HENDRA_&_NIPAH_FINAL.pdf . -Mod.AS.

A HealthMap/ProMED-mail map can be accessed at: http://healthmap.org/r/1z_*.]

See Also