If there are any doubts as to how much interest has been generated by last week's second announced outbreak of HPAI H5N2 in Western Russia, we have our 2nd analysis of the day (see my earlier blog Brief ESA Report On HPAI H5N2 & H5Nx In Russia) - this time from the UK's DEFRA (Department for Environment, Food and Rural Affairs)
As with this morning's report from France's ESA (Epidemiosurveillance Santé Animale), there are far more questions about the origins and scope of Russia's HPAI H5N2 problem than answers.Similar to comments from the ESA report, the DEFRA authors write:
There are still uncertainties around the source of infection of the H5N2 HPAI affected flock and whether there is wider virus circulation in the area or if wild birds will be capable of transmitting the virus.The fact that in 2018, we are still forced to play guessing games about the specifics of infectious disease outbreaks should provide no one comfort - yet it incredibly remains more the rule than the exception in many parts of the world.
Follow the link to read the full report.
Department for Environment, Food and Rural Affairs
Animal & Plant Health Agency
Advice Services Team - International Disease Monitoring
Preliminary Outbreak Assessment
H5N2 HPAI poultry in Western Russia
17 August 2018
Ref: VITT/1200 Avian Influenza in Russia
The Russian authorities have reported an outbreak of H5N2 HPAI in a commercial farm of nearly 500,000 birds in Kostromskaya region, NW Russia (OIE, 2018; see map).
According to the disease report, sequencing analysis showed the virus belonged to the Asia lineage (clade 18.104.22.168) which is the clade of H5 HPAI viruses which has been detected in multiple wild bird and poultry cases across Asia, Africa and Europe since 2014.There have been no human cases associated with H5N2 HPAI infection in areas where it circulates.
Since early June, 67 outbreaks of H5 have been reported in commercial poultry across several regions of western Russia including Orlov, Saratov, Kur, Smolensk, Samar, Rostov and Penzen. In July, a new focus of circulating virus in Tatarstan, Nizhegorod, Chuvash, Udmurt, Ul’Yanov and Mariy-El regions was reported, in backyard flocks but there is no information on the full strain identification. As we are approaching the autumn migration season, the risk to the UK will start to increase.
If these outbreaks are all caused by the H5N2 HPAI virus and if this virus is not poultry-adapted and therefore can jump into wild waterfowl, then migratory waterfowl may have only partial immunity if they were exposed to H5N6 HPAI last year or H5N8 HPAI in the previous year. The pathogenicity in wild birds is not known, and the source of infection is also unknown. If wild birds are involved in long distance movement of the virus, then poultry farms in NE and NW Europe may be at risk in the coming months.
The latest outbreak of H5N2 HPAI is overlapped by three migration flyways – the Central Asian, the West Asian and the East Atlantic and it is this flyway which also brings wild migratory waterfowl to the UK.
H5N6 HPAI has also recently been reported in a wild mute swan (Cygnus olor) in Denmark, therefore this virus is still present in some areas of Europe and certain wild bird species.
The EU/OIE/FAO international reference laboratory/UK national laboratory at Weybridge has the necessary ongoing diagnostic capability for these strains of virus, whether low or highly pathogenic AI.
There are still uncertainties around the source of infection of the H5N2 HPAI affected flock and whether there is wider virus circulation in the area or if wild birds will be capable of transmitting the virus. Therefore we will keep the situation under review.
Overall, it is considered that the risk of further outbreaks of H5N6 in wild birds in the UK is “LOW”. The presence of H5 HPAI in southern Europe and western Russia poses a “VERY LOW” risk to wild birds in the UK because there are no waterfowl that migrate from these regions at this time of year but this will change in the next few weeks as the birds start to leave their breeding grounds. Other pathways for incursion through legal trade remain negligible.
We strongly recommend that all poultry keepers (including backyard keepers) should familiarise themselves with government guidance on good biosecurity and how to report suspicion of disease appropriately.
Further information is available here: https://www.gov.uk/guidance/avian-influenza-bird-flu
including updated biosecurity advice for poultry keepers for
England; http://gov.wales/topics/environmentcountryside/ahw/poultry/bird-gatherings- advice/?lang=en for Wales and; http://gov.scot/avianinfluenza for Scotland
We ask that the public use the Defra helpline (Tel: 03459 33 55 77) to report findings of dead wild birds where there are three or more of wild ducks, wild geese, swans, gulls, or single birds of prey or where there are more than five birds of any other species found dead in the same location.
Dr Helen Roberts