Bird flu, also known as avian influenza, is a viral infection that can infect birds and some mammals. There has been an increase in cases of bird flu detected in the UK in recent months. This article will examine where the cases have been detected and provide information on the current situation.
What is bird flu?
Bird flu is caused by an influenza A virus. There are many different strains of avian influenza viruses that can infect birds. Some strains, such as H5 and H7 subtypes, can cause significant outbreaks in poultry.
In rare cases, certain bird flu viruses can also infect humans, such as the H5N1 strain. When bird flu viruses infect people, it is called “avian influenza” or “bird flu” in people. The viruses do not infect people easily and when they do, spread from person to person appears limited. However, because all influenza viruses have the ability to change and mutate, scientists are concerned that bird flu viruses one day could change and become able to infect people easily and spread easily from person to person, causing a pandemic.
Current situation in the UK
There has been a significant rise in cases of bird flu detected in the UK in recent months. According to the Department for Environment, Food & Rural Affairs (Defra), since late October 2021 there have been over 200 cases of highly pathogenic avian influenza (HPAI) H5N1 confirmed in kept birds and wild birds in the UK.
This is the largest ever outbreak of bird flu in the UK and it has been declared an Avian Influenza Prevention Zone (AIPZ) across Great Britain. Within this zone, all bird keepers are required by law to follow strict biosecurity measures.
Cases in England
The majority of cases detected have been in England. As of March 2022, Defra reports over 190 cases in England. These cases have been found in both kept birds on farms and in backyard flocks, as well as in wild birds.
The cases have been widely distributed across England, affecting East Anglia, the Midlands, Devon, Lancashire, North Yorkshire and Cumbria. There have also been cases detected near London.
Some of the largest outbreaks were seen in Norfolk, where over 35 cases were detected across several farms.
Cases in Wales
There have been around 35 cases of bird flu confirmed in Wales since October 2021. These have included a number of small backyard flocks and larger outbreaks on commercial turkey and chicken farms.
Cases have occurred across North and mid Wales, including on Anglesey, near Wrexham and in Powys.
Cases in Scotland
Scotland has seen around 10 cases of highly pathogenic H5N1 avian flu since late 2021. The cases have been found across central and southern Scotland and the Highlands, affecting several types of kept birds.
Several cases were identified in wild birds across Scotland as well. Migratory wild birds may play a role in transmitting the virus over long distances during migration.
Type of birds affected
The bird flu outbreak in the UK has affected a range of different types of birds:
- Chickens on commercial egg and meat farms
- Ducks and geese on commercial farms
- Turkeys on commercial farms
- Game birds raised for shooting
- Pet birds such as chickens, ducks and geese
- Zoo birds such as penguins and parrots
- Wild waterfowl and sea birds
Defra reports that the most significant impact has been seen in turkey flocks, with over 500,000 birds culled due to outbreaks since last October. However, all types of kept birds and wild birds are at risk.
Measures taken to control the outbreak
The UK government has taken a number of steps to try to control the bird flu outbreak, including:
- Declaring a nationwide Avian Influenza Prevention Zone requiring enhanced biosecurity for all bird keepers
- Implementing cleansing and disinfection procedures on infected premises
- Culling of all birds on infected premises
- Temporary control zones introduced around infected premises to restrict movement of birds
- Banning all poultry gatherings, markets, shows and fairs
- Requiring all kept birds to be housed or otherwise kept separate from wild birds
- Increasing surveillance and testing of wild bird carcasses and routine testing on farms
These measures aim to limit the spread of the virus between captive flocks and reduce contact with wild waterfowl that can introduce the virus. However, with the virus circulating widely in wild birds, eradication is unlikely.
Risk to human health
The risk to human health from the current H5N1 outbreak remains very low according to public health authorities. Human infections with bird flu viruses are extremely rare, and transmission between humans is limited.
There have been no known cases of humans infected with H5N1 from this outbreak in birds in the UK. The Food Standards Agency has said that bird flu poses a very low food safety risk. Properly cooked poultry and eggs are safe to eat.
However, people in close contact with infected birds are advised to wear protective clothing and follow good hygiene practices. Some antiviral medications are also available for treatment if required.
Will it spread to pets or other animals?
There is minimal risk to humans from infected pets. Cats and dogs are not easily infected with avian influenza viruses. However, there have been some rare cases around the world of H5N1 infections in big cats like tigers and leopards that ate infected bird meat.
Rabbits and other mammals are also not typically affected by bird flu. It remains primarily a disease of birds.
However, as a precaution it is recommended to keep pets away from wild birds and not to allow them access to raw poultry products or carcasses of dead wild birds.
Conclusion
The UK is currently undergoing the largest outbreak of highly pathogenic H5N1 avian influenza on record. Over 200 cases have been confirmed across England, Wales and Scotland since October 2021, primarily affecting turkey flocks but also chickens, ducks, geese, pet birds and wild bird populations.
The government has introduced strict biosecurity requirements for all bird keepers and is taking action to control the outbreak, including large-scale culling on infected premises. However, the virus is expected to continue circulating in wild bird populations, making eradication difficult.
The risk to public health remains very low and properly prepared poultry is safe to eat. But vigilance is needed to limit the impacts on commercial and backyard flocks. Ongoing surveillance and biosecurity will be required to protect kept birds from continued flu outbreaks.