Russian authorities have confirmed an outbreak of avian influenza on a 500,000-bird commercial farm in Kostromskaya, a region to the north-west of the country.

According to the disease report, sequencing analysis showed the virus (H5N2) belonged to the Asian strain 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 (highly pathogenic avian influenza) infection in areas where it circulates.

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.

Therefore, as the autumn migration season approaches, the risk to the UK will start to increase.

If wild birds are involved in the long-distance movement of the virus, poultry farms in north-east and north-west Europe may be at risk in the coming months.

Since early June, 67 outbreaks of H5 have been reported in commercial poultry across several regions of western Russia. However, in backyard flocks there is no information on the full strain identification.

If Russia’s 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.

Risk to the UK

Overall, the Government considers 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.

However, Defra warns this will change in the next few weeks as the birds start to leave their breeding grounds.

A Defra spokesman said: “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.”