Avian influenza

What is avian influenza?

Avian influenza (AI or ‘bird flu’) is an infectious disease which mainly affects birds, including chickens, turkeys, pheasants, quail, ducks, and geese. It can also affect mammals, including humans. The UK Health Security Agency (UKHSA) has said the risk to the general public’s health from AI is very low.

The most serious type of AI, known as highly pathogenic avian influenza (HPAI), can cause symptoms in birds such as breathing difficulties and swelling and can lead to a bird’s sudden death.

Is it the UK’s worst ever outbreak?

The 2021-22 AI outbreak is the worst ever seen in the UK. For the first time, an outbreak has continued uninterrupted from one winter to the next. In 2022, infected wild birds were found over the summer months when normally there are no or very few cases. AI levels have now risen significantly, with wild birds moving around with the colder autumn weather and infecting more kept birds.

Since October 2021, there have been 256 confirmed cases of the type of HPAI known as H5N1 in England. 136 of these cases have occurred since 1 October 2022. AI lives in aquatic birds and wild birds, meaning there is a reservoir of disease that is impossible to eradicate. HPAI viruses spread via faeces, water and contaminated materials and can exist in bird waste for several months. Domestic poultry are especially vulnerable, and AI can spread very rapidly in flocks.

Why is AI spreading so rapidly?

Scientists are not clear about the reasons why AI is spreading so rapidly and has been persistent since autumn 2021. Two leading theories are that genetic mutations have increased the virus’s ability to replicate and spread more efficiently than previous strains. Another is that mutations have allowed the virus to infect a broader range of species. Some animal welfare groups have said the dense stocking of poultry leaves flocks open to the rapid spread of the virus after an initial infection.

Where disease is confirmed in kept birds, flocks may be culled to limit its spread. Between 1 October and 15 November 2022, approximately 3.4 million birds died or were culled for avian influenza control purposes in the UK. Since 2021, around 50 million AI infected birds have been culled across Europe. The outbreak has also had a significant impact on wild birds, infecting more than 60 species and causing a dramatic rise in deaths in the UK’s globally significant seabird colonies.

What is the Government doing to stop the spread of AI?

The Government’s AI mitigation strategy includes imposing Avian Influenza Prevention Zones (AIPZs) where keepers of birds must adopt improved biosecurity measures, such as washing equipment and keeping birds away from contact with wild birds. Managing AI is a devolved matter.

An AIPZ was declared in October 2022 across Great Britain and in November in Northern Ireland. Subsequently, an avian influenza housing order was introduced in England from 7 November. This is where keepers are required to house birds or use netting to separate them from contact with wild birds. An avian housing order was also introduced in Northern Ireland from 28 November. Housing measures come in across Wales from 2 December. Scotland does not currently require birds to be housed but is keeping this under review.

Where disease is confirmed in flocks, the UK Government and Devolved Administrations require poultry and bird keepers to take additional biosecurity precautions and can require flocks to be culled. The Government pays compensation for healthy birds from the start of culling. The Government relaxed marketing rules in England in October 2022 to allow poultry to be slaughtered early so turkeys and other birds could be frozen and then sold in time for Christmas.

What are stakeholder and political views?

Farmers are calling for more Government action on compensation for culled birds, particularly as only healthy birds are eligible for compensation. Delays in government vets attending premises can mean birds contract the disease before they can be culled.

Animal welfare groups are concerned that intensive farming is adding to the spread of AI and that mitigation measures worsen animal welfare through dense housing of birds and poor husbandry practices.

Opposition MPs have criticised the Government for not introducing a requirement for keepers to house their birds sooner