US authorities have reported finding wild birds in Washington state infected with two different highly pathogenic avian influenza (HPAI) viruses, H5N2 and H5N8, raising questions about possible connections with recent H5N2 outbreaks across the border in Canada and with an Asian H5N8 strain that is now hitting European poultry farms.
In reports to the World Organization for Animal Health (OIE), the US Department of Agriculture (USDA) said H5N2 was found in a wild pintail duck, while H5N8 was found in a captive wild gyrfalcon that was fed on hunter-killed birds. Both birds were in Whatcom County, Washington, which borders the Abbotsford area of British Columbia, the site of recent H5N2 outbreaks in poultry.
Also, Italy has become the fourth European country in the past few weeks to report an H5N8 outbreak in poultry, with an outbreak on a turkey farm, and Germany reported a second poultry H5N8 outbreak at a site distant from its first H5N8 event.
An OIE report does not comment on whether the H5N8 virus found in the US is related to the H5N8 currently circulating in Europe. It says the hemagglutinin component (H5) of the H5N2 virus is related to a virus isolated from a bean goose in Korea this year, while the neuraminidase (N2) component of the H5N2 isolate is similar to that from a virus found in a US green-winged teal in 2007.
Italian veterinary authorities, in reporting their H5N8 outbreak to the OIE, said the virus killed 1,219 of 31,985 turkeys on a farm near Venice in northeastern Italy’s Veneto province.
The report said culling of the surviving turkeys to control the outbreak would begin imminently and that other control measures would be applied in a restriction zone around the farm. Officials also said they are sequencing the virus to determine its genotype.
Italy follows Germany, the Netherlands, and the United Kingdom in reporting recent outbreaks of H5N8 in poultry. Germany was the first, with a report of the virus on a turkey farm on Nov 4, and outbreaks were reported on chicken and duck farms in the Netherlands and the UK shortly afterward. At least four farms in the Netherlands have been struck by the virus.
A further outbreak has also been reported in Germany on Dec 16th on a turkey farm near Barßel, Lower Saxony. The H5N8 avian influenza was detected within the turkey population of the farm and because of that, all the farms animals are to be killed with gas.