Avian influenza

What is avian influenza?

Image of a duck

There are two types of avian influenza:

  • High pathogenicity (HPAI) which is the more virulent type formerly known as fowl plague which often results in up to a 100% flock mortality.
  • Low pathogenicity (LPAI) which usually only causes mild respiratory disease in domestic poultry.

LPAI infections may cause less severe suffering, but this may be over a longer period. Also, exacerbation of LPAI by other organisms and environmental conditions could also cause substantial welfare problems in infected poultry.

Risk to humans

AI viruses may represent a risk to humans, either by direct infection, which can be fatal, or as a result of mixing with human influenza virus. This may result in the emergence of a pandemic virus.

VLA's role is to:

  • provide a rapid, reliable diagnostic service for statutory tests.
  • provide an international reference laboratory service.
  • improve diagnostic methods of virus detection and characterisation.
  • improve our understanding of virus virulence, host range, host adaptation and disease pathogenicity.
  • improve our understanding of avian influenza epidemiology.

International Reference Laboratory

As the International Reference Laboratory for avian influenza, VLA carries out confirmatory tests on samples from many other countries. These are processed as rapidly as possible after receipt at the laboratory. Anyone seeking the results of these tests should contact the authorities in the respective country of origin.

An alternative source of information is the OIE table of avian influenza notifications.

Genetic data

VLA as the EU/OIE/FAO reference laboratory for avian influenza is currently seeking to secure agreement to release genetic data related to the current H5N1 incidents in Europe for the benefit of the scientific community.

Although some data is preliminary and analysis is still in progress we will be seeking approval from countries submitting viruses and other materials to VLA Weybridge for permission to share such data so that confidentiality is not compromised.

Avian influenza is a notifiable disease and therefore you must contact your local
Animal Health Office if you suspect signs of this disease.

Defra has published advice for bird keepers on how you can protect your birds from avian influenza.