#16,422
Although it has taken a backseat to the COVID pandemic and the emergence of the Omicron variant over the past few weeks, the UK and Europe continue to endure their second record-breaking avian H5 epizootic in less than a year.
Three weeks ago, in OIE Calls For Increased Surveillance Against Avian Influenza As Outbreaks Intensify Around The Globe, we looked at renewed concerns over the spread of potentially zoonotic HPAI H5 viruses around the world.
While primarily a threat to poultry and wild birds, last spring the European H5Nx clade 2.3.4.4b viruses were recognized to have some zoonotic potential (see CDC Adds Zoonotic Avian A/H5N8 To IRAT List).
Today DEFRA has published their latest update, in the form of a 16-page PDF. I've posted some excerpts, but download the report to read it in full.
Updated Outbreak Assessment #6Highly pathogenic avian influenza (HPAI) in the UK,and Europe
13 December 2021 Ref: VITT/1200
HPAI in the UK and Europe Disease Report Since our last outbreak assessment on 06 December 2021, there continue to be reports of highly pathogenic avian influenza (HPAI) H5 both in Europe and in Great Britain (GB).
There have been a further 15 confirmed report cases in GB of HPAI H5N1 in domestic poultry or captive birds since our last assessment, with three in backyard (or captive bird) premises, and 12 in commercial premises. Northern Ireland have reported HPAI H5N1 in two premises.
According to the OIE, there continue to be high numbers of reports of HPAI H5 in Northern Europe over the past week. Since 06 December, Belgium, France, Germany, Hungary, Ireland, Poland and Russia have reported further outbreaks of HPAI H5N1 in domestic poultry. To 13 December, the Republic of Ireland (RoI) has confirmed HPAI H5N1 at a further two premises. One close to the border of Co Amargh and Monaghan and a second close to the border of Co Cavan and Co Fermanagh. RoI has reported 50 cases of HPAI H5N1 in wild birds to date, with a housing order brought into effect on 22 November (DAERA, 2021).
Wild bird HPAI H5N1 cases continue to be reported in north-west Germany, the coastal regions of the Netherlands, Luxembourg, Denmark, and Sweden. Greece and Portugal have also reported their first cases of HPAI H5 this season.
(SNIP)
Conclusion
New cases of HPAI H5 in wild birds and outbreaks in poultry continue to be reported in northern Europe including in the UK and the Republic of Ireland since our last assessment.
Total numbers of migrating wild water birds (ducks, geese, and some swan species) may now be peaking in GB and the majority of wintering water birds have now arrived. Multiple confirmed cases of HPAI H5 in wild birds (235 to 13 December 2021) across a range of species, including resident sedentary species such as raptors and mute swan indicating that they had been exposed to infection in GB. Furthermore, potential bridging species such as gulls and raptors have tested positive. More wild bird HPAI H5 infections are expected including in sedentary GB species and potential bridging species. HPAI H5 will continue to circulate in both susceptible migrant water birds and sedentary bird species within the UK over the next few months, with a greater number of events likely to be observed around water bird wintering sites. The risk level of HPAI H5 in wild birds is therefore maintained at VERY HIGH across GB.
The risk of exposure of poultry across the whole GB is maintained at MEDIUM (with low uncertainty) where good biosecurity is applied, and at HIGH (with low uncertainty) where biosecurity is suboptimal. This assessment takes into consideration the Avian Influenza Protection Zone (AIPZ) and assumes that bird keepers are taking the additional biosecurity measures required.
On 24 November, the Chief Veterinary Officers for England, Scotland, Wales, and Northern Ireland announced housing measures, which came into force on the 29 November 2021. It is now a legal requirement for all bird keepers to keep their birds indoors, to exclude contact with wild birds, and to follow strict biosecurity measures in order to limit the spread of and eradicate the disease. These housing measures build on the strengthened biosecurity requirements that were introduced as part of the AIPZ in GB on 3 November 2021, and in Northern Ireland on 17 November 2021.
We are continuing to closely monitor the situation.
While less dramatic, the east Asian nations of South Korea and Japan continue to report outbreaks in wild birds, and in poultry holdings. This fall Japan has reported 9 poultry outbreaks in 8 Prefectures while South Korea reports 13 confirmed (and 1 suspected) outbreak of HPAI in poultry.
Despite reporting a record number of human H5N6 infections in 2021 (n=31) - presumably spread by infected poultry - China's MOA hasn't reported a poultry outbreak of HPAI in more than a year, and only one outbreak in wild birds since early June.
Getting good information out of China is always difficult, but has become even more so since the pandemic began.
For now, Europe's HPAI H5 virus has only demonstrated a modest ability to infect humans, and China's H5N6 hasn't developed the ability to transmit efficiently from human-to-human.
The health threat to the general public from these viruses remains very low, and it is mainly of concern to those who work closely with poultry. The economic losses due to these outbreaks can be enormous, however.
The evolution of these viruses continues, and what may not pose a great threat today could change down the road. So we track them with more than just academic interest.
