The outbreak, caused by the H7N7 serotype of the disease, affected layers. The company also owns four other laying premises and two pullet-rearing premises, which provide the birds for the egg businesses.

The report was released by the Animal and Plant Health Agency (APHA), and explains that the outbreak likely resulted from an incursion of the low pathogenic version of the disease onto the infected premises, which then mutated into a highly pathogenic virus.

The report says that there is uncertainty surrounding the route of the low pathogenic virus incursion, which it says must have happened between the end of May and mid-June, before the virus mutated more towards the end of June.

However, it identified wildfowl on ponds on the premises as the likely source of the virus, suggesting it then moved to free range chickens by indirect contact. The evidence for this hypothesis comes from the fact that the wild birds were near to the first shed to be infected, and the genetic sequence of the virus suggested a recent move from wild birds to poultry.

The report says the virus appears to have been confined to the single infected premises, because after extensive investigations, scientists could find no evidence of any other poultry businesses being infected.

Further Reading

To read the full report into the Lancashire bird flu case, click here.

Click here to visit our bird flu page.