Cases of bird flu, or avian flu, have spiked this past week with Norfolk facing several outbreaks across the county.

Council leaders have described the situation as "unprecedented" and thousands of birds have been culled at farms in recent days.

Recent months have seen 160 confirmed cases across the country in the UK's worst-ever bird flu outbreak, and the fourteenth in Norfolk and Suffolk since the start of September.

But what is bird flu and what is causing it to become such a problem in the region?

What is avian flu?

Avian flu, or bird flu, is a virus that causes disease in birds, including poultry, pigeons and wild birds, according to the RSPB.

It has been found at scores of poultry farms and commercial premises across the UK in the past year, while the disease has also ripped through breeding colonies of seabirds, killing thousands in some sites.

A spokeswoman for the charity said: "Like other viruses there are lots of different strains, most of which cause no or few signs of disease in infected wild birds.

"By contrast HPAI (which is causing the current outbreak) can cause severe disease and high mortality"

How is it spread?

The virus is spread via infected bird faeces, nasal secretions, and saliva.

"Wild birds are often more resistant than domestic ones to bird flu and can carry the disease without showing symptoms" said the RSPB.

"This has led to speculation that they are main cause of spreading, but there are several ways. Globally the most significant has been the unrestricted movement of poultry and poultry products."

What is the situation in Norfolk?

Tens of thousands of turkeys, chickens and ducks have been culled after recent outbreaks in Norfolk.

Norfolk County Council has described the situation as "unprecedented" and in the past weeks six sites in Norfolk have been affected.

If you were worried about a shortage of Christmas turkeys, farming leaders have said there should still be enough to go around.

Last week, the intensifying outbreak in the east of England sparked a raft of new restrictions in a bid to halt the spread of the disease.

The regional Avian Influenza Prevention Zone (AIPZ) makes it a legal requirement for all bird keepers across Norfolk, Suffolk and parts of Essex to follow strict biosecurity rules including disinfecting clothing, footwear, equipment and vehicles before and after contact with captive birds.

What impact is it having upon wildlife?

While wild birds are often more resistant, the current outbreak is having a "devastating impact" upon wild populations.

AN RSPBA spokeswoman said: "This summer, dead and dying seabirds have been reported right round the coast of the UK.

"This is extremely worrying as the UK hosts international important breeding seabird populations, particularly in Norfolk.

"Most affected are great skuas and northern gannets.

"Scotland, for example, holds 60pc of the world’s breeding population of great skuas and at some colonies over 70pc of birds have died this year.

"Other seabirds affected by the virus around the UK include common guillemot, Atlantic puffin, razorbill, black-legged kittiwake and northern fulmar, gulls and terns.

"Species other than seabirds have also been affected. For example HPAI has now been confirmed in 6 species of raptor in Scotland: white-tailed eagle, red kite, golden eagle, buzzard, kestrel and sparrowhawk.

Bird flu has been found in small numbers of foxes, harbour seal, grey seal and otter. It has recently been found in cetaceans (summer 2022) – bottlenose dolphin and harbour porpoise."

How do you spot the virus in birds?

Avian flu can cause a large number of different symptoms, ranging from sneezing, gurgling, lethargy and depression.

A sudden and rapid increase in the number of dead birds in an area can be a clear sign of bird flu, according to the RSPB.

Can it affect humans and pets?

Human infections are rare and the risk to the general public’s health is very low. However, some strains of the viruses, such as H5N1 or H7N9, have been associated with human disease.

Almost all reported human transmissions globally have come from extremely close contact with infected birds.

The RSPB is encouraging people not to have close contact with sick or injured birds.

Close contact includes touching infected birds, contact with droppings or bedding and killing or preparing infected birds for cooking.

The RSPB also recommends dog walkers avoid areas where there is known to be bird flu.

A spokeswoman said: "Do not allow your dog to go into areas where there are sick or dead birds and keep them on a short leash."

What can people do to help?

People should report suspected cases of bird flu to the Department for Environment, Food and Rural Affairs (Defra).