Photo Credit – FAO
While H5N1 gets most of our attention, there are many varieties of avian influenza including H7s and H9s. Some are highly pathogenic (HPAI) and produce high rates of morbidity and mortality in flocks – while others are of lower pathogenicity (LPAI).
The OIE requires their notification whenever an avian influenza of the H5 or H7 strains are identified, because these strains have a history of evolving from LPAI into HPAI strains.
We’ve seen many non-H5N1 outbreaks in local poultry operations in places like the UK, Mexico, and Canada. And while exceeding rare, we’ve seen sporadic human infection from these strains as well (see MMWR: Mild H7N3 Infections In Two Poultry Workers - Jalisco, Mexico).
If not quickly contained, these outbreaks can force the culling of tens of millions of bird and can inflict devastating economic losses.
Today authorities in Australia’s state of New South Wales are reporting a suspected outbreak of an as-yet unidentified avian influenza (not suspected to be H5N1) at a hen facility in the Lower Hunter region.
Details are a bit scant, but here is the official release from the NSW Department of Primary Industries.
15 Nov 2012
The Department of Primary Industries (DPI) has quarantined a layer hen facility in the Lower Hunter region following a suspect case of Avian Influenza.
"The suspected virus is definitely not the highly pathogenic H5N1 strain that has gained worldwide attention — nor is it closely related to that strain," NSW Chief Veterinary Officer Ian Roth said.
"Australia has previously had a small number of outbreaks of Avian Influenza viruses which were all quickly and successfully eradicated.
"The property has been placed under quarantine and initial tracing and surveillance is being undertaken to confirm that the virus hasn’t spread. We currently have no evidence to suggest it has.
"DPI’s First Response Team has been dispatched to monitor the locked-down property."
Dr Roth said the peak egg industry body Australian Egg Corporation has been advised and the property owners are co-operating with authorities.
"We are still waiting on final confirmation from CSIRO’s Australian Animal Health Laboratory which is expected later this afternoon," Dr Roth said.
Dr Roth said people who notice sick or dead birds should contact their local veterinarian or call the Emergency Animal Disease Watch Hotline 1800 675 888.
For further information on avian influenza is available.
Beyond the question of the type of avian influenza at work here will come questions on how this virus was introduced into this flock.
Although Australia has been largely spared from avian influenza outbreaks over the past decade, this is not the first incident reported in 2012.
In Janaury a duck farm in Victoria was depopulated due to a LPAI outbreak. Although the strain is not identified in the government press release below, according to the OIE REPORT it was an LPAI H5 strain.
6 June 2012
In January 2012 The Department of Primary Industries (DPI) quarantined a commercial duck farm in two locations north-west of Melbourne after birds there tested positive to Low Pathogenicity Avian Influenza (LPAI).
To prevent spread of the disease, and in accordance with the Livestock Disease Control Act 1994, the Minister of Agriculture declared Restricted and Control areas around the infected properties in which movement of birds and eggs was restricted.
Subsequently, the infected properties were depopulated and decontaminated and the results of surveillance have shown that LPAI is no longer present. On 5th June 2012 the Minister revoked the movement restrictions around the infected properties.
I’ll post an update to this blog when CSIRO releases their analysis of the strain.