UK raises risk level for highly-pathogenic bird flu

Defra has raised its official risk level for high path avian influenza in the UK following the outbreak
Defra has raised its official risk level for high path avian influenza in the UK following the outbreak

The official risk level for highly pathogenic bird flu has been raised following the spread of the virus amongst wild birds on the migration route to the UK.

Highly pathogenic H5N1 was discovered at a site near Droitwich Spa, Worcestershire. A three kilometre protection and a 10km surveillance zone are in force around the premises.

UK chief veterinary officer Christine Middlemiss said: “H5N1 avian influenza has been confirmed at a wild bird rescue centre in Worcestershire. We have taken swift action to limit the spread of the disease and any birds at risk of infection will now be humanely culled.

“UK Health Security Agency has confirmed that the risk to public health is very low and the Food Standards Agency has said that bird flu poses a very low risk to food safety for UK consumers.

“As we move into the higher risk period over winter bird keepers should pay extra attention to the health of their birds. Anybody who suspects disease should report it to their vet or APHA immediately.

"The best way to tackle this disease is for poultry keepers to ensure that they have strong biosecurity measures in place.”

The discovery coincided with Defra’s latest situation update on avian influenza. The department said that “while there have been no further HPAI H5N8 outbreaks in captive birds in north-east France, Belgium and Luxembourg since our last report, HPAI H5N1 is spreading in wild birds along the wildfowl migration flyway in northern Germany and Denmark.”

It warned “there is evidence that there have been significant changes in the epidemiology of highly pathogenic avian influenza (HPAI) H5 in Europe.”

As a result of the developments, Defra raised its official risk level for high path avian influenza. “There is evidence that there have been significant changes in HPAI H5 epidemiology in Europe to warrant increasing the risk of incursion of HPAI H5 via wild birds in GB from low to medium."

“The risk of poultry and captive bird exposure to HPAI H5 across the whole GB is still low (with medium uncertainty) where biosecurity is sub-optimal, and low (with low uncertainty) where stringent biosecurity measures are applied.

"We are in a period of rapid seasonal change with respect to these risks and will continue to closely monitor the situation.

"This increase in wild bird risk incursion coincides with the proposed decrease in threshold of collecting reported dead wild birds from five to just one from the list of target species, thereby increasing the sensitivity of detection of the wild bird surveillance scheme.”

They said that with ongoing detections in wild bird populations not only in central Asia and southern Russia, but also nearer to Britain in northern Germany, Denmark and the Netherlands, together with the imminent arrival of more migratory waterfowl, the risk level to Britain may well increase further through the autumn and into the winter.

The UK’s chief veterinary officers had recently urged poultry keepers to take action to reduce the risk of avian flu over the winter. They said the risk of migratory wild birds infecting domestic poultry would rise and it was vital that poultry farmers and bird keepers took action to improve biosecurity standards.

In its latest situation report, Defra said that species affected by spreading bird flu in northern Europe would be migrating further west into Britain.

Many have already arrived, with high numbers of wigeon still expected across GB, peaking in December,” said Defra in its report.

“Furthermore, this H5N1 strain in wild birds requires full characterisation to determine the genetic relationships in comparison to H5N1 viruses detected in spring/summer to establish if they have derived from local recrudescence or relate to new introductions to Europe of a related or identical virus,” it said.

Defra said HPAI H5 infection in Europe over the autumn/winter season of 2020/2021 was unprecedented. There were numerous positive HPAI H5 incidents reported in domestic poultry and wild birds through spring and summer particularly in the low countries of north-west Europe and the Baltic Sea coast.

"These events, said Defra, were most probably linked to “extensive infection pressure from the winter period and environmental survival of virus including near to poultry production premises. The UK reported 24 outbreaks in poultry and captive birds during autumn/winter 2020/2021.”

In the autumn period of 2021 the first H5N1 reported cases were in barnacle geese in southern Finland in early September, perhaps representing the start of a new wave of HPAI spreading west in migratory waterbirds.

Subsequently Germany reported H5N1 HPAI to OIE in unidentified wild geese species in Schleswig-Holstein on its north-west coast in mid-October. There have also been reports of further cases of H5N1 in wild ducks in north-west Germany, Denmark and the Netherlands.

Outbreaks of H5N1 in poultry have also been reported in Europe. There has been an outbreak of H5N1 in turkeys in October in northern Italy. This involved a flock of nearly 13,000 turkeys in the province of Verona. Another case was in backyard birds in the Czech Republic at the end of September.

Finland reported four events of H5N1 detected in late September in ring-necked pheasants, including three groups of several thousand birds released as game birds earlier this year.

Elsewhere in Europe, H5N1 has been detected in a white-tailed eagle in Estonia in mid-October. Russia has reported 18 H5/H5N1 events in captive backyard/village birds and three H5 outbreaks in poultry farms starting late September/early October. Ukraine has reported an H5 outbreak in backyard birds detected in mid-October.

The UK’s four chief veterinary officers published a joint statement, in which they said: “Avian flu is a continued threat to all poultry keepers, and as winter approaches we need to be ready for the increased risk of disease that migrating birds pose to our flocks.

“We encourage keepers across the UK to implement strong biosecurity practices now, including regular shed maintenance checks, cleaning and disinfecting footwear and signing up for our email and text alerts.

"Making these tasks a regular fixture of your disease control plans now will make a significant difference in the fight against avian flu this winter and for years to come.”

A detailed investigation is in progress to determine the most likely source of the outbreak.