#13,673
Over the past 6 months HPAI H5N8 activity has been subdued across most of Europe, with the lone exception of Bulgaria, which has continued to report outbreaks throughout the summer and fall.
Two weeks ago we saw Bulgaria's BVBH Reports Two More Avian Flu Outbreaks In Haskovo District, with 3 additional outbreaks in October alone (see here, and here).Just over a week ago, in Bulgaria's NVS Imposes Stricter Avian Flu Biosecurity Rules, we saw some of the societal impacts - and protests - over attempts to reign in these outbreaks.
Because many migratory birds are overflying Bulgaria via the Black Sea / Mediterranean flyway, the concern is that they might pick up and distribute these avian viruses on their southbound trek to Southern Europe, the Middle East and North Africa (see WHO: Migratory Birds & The Potential Spread Of Avian Influenza).
While the UK sits under a different, albeit adjacent (East Atlantic) flyway, these flyways all overlap, and therefore allow for lateral (east-west) movement of birds (and viruses) as well.The UK's DEFRA has released the following Situation Report on the risks of continued H5N8 activity in Bulgaria. I've only posted some excerpts from a longer report, so follow the link to read it in its entirety.
Situation Assessment #5
Avian Influenza (H5N8) in Bulgaria
9 November 2018
Ref: VITT/1200 HPAI in Bulgaria
Disease report
The Bulgarian authorities have now reported 24 outbreaks of HPAI H5N8, including 9 outbreaks in October (OIE, 2018). These outbreaks in October have been reported in commercial premises with laying hens (39,000) and ducks (between 1,000 birds and 16,000 birds), small commercial farms (fewer than 500 birds) and one very large commercial premises (130,000 birds). Four regions have been affected to date (see map, below)
Situation assessment
Eradication and control measures according to the Council Directive 2005/94/EC have been put in place, including 3km protection zones and 10 km surveillance zones around each infected premises, a ban on live poultry markets and exhibitions of live birds, and biosecurity measures at infected premises.
In addition to these measures, there has been enhanced active surveillance at all commercial breeders, layers and waterfowl premises since May, where poultry have been sampled and serological testing has been performed every 21 days for a period of three months, followed by a final sampling visit 50 to 60 days later.
Of those sampled, 25 duck farms to date have been H5N8 HPAI sero-positive, but virus could not be isolated from these farms (PAFF, 2018). Interestingly, recent data reported in the EFSA scientific overview for May to August 2018 documents the latest scientific research on the H5N8 HPAI viruses from the 2016 epizootic, concluding that the virus is avian adapted with increased virulence for waterfowl and higher rates of oropharyngeal rather than cloacal shedding (EFSA, 2018).
However over time these viruses naturally attenuate in domestic waterfowl (but retain their HP phenotype in galliforme species) and result in milder disease signs which provides an explanation for the detection of serologically positive flocks in the absence of virus being isolated.
(SNIP)
Conclusion
The EU/OIE/FAO international reference laboratory/UK national laboratory at Weybridge has the necessary ongoing diagnostic capability for these strains of HPAI virus.
Overall, it is considered that the likelihood of any notifiable avian disease in wild birds in the UK remains LOW, however this will be kept under review and may change as the migration season is now underway along the East Atlantic flyway – the risk to the UK will depend on the presence of AI in wild birds and the westward movement along this route, which is affected by the weather. H5N6 HPAI is still circulating in the wild bird fauna of this flyway, but H5N8 HPAI has not been reported since 2017.
The presence of H5N8 HPAI in Bulgaria does not change the risk level for the UK at present. There is no trade in high risk commodities and the migratory wild waterfowl flyways are different.
Nevertheless, we recommend that all poultry keepers stay vigilant and make themselves aware of the latest information on gov.uk, particularly about recommendations for biosecurity and how to register their flocks using the simplified forms now available.
We will continue to report on any updates to the situation and in particular any changes in disease distribution or wild bird movements which may increase the risk to the UK
