Research by Wageningen Bioveterinary Research shows that the risk of transmitting a highly pathogenic bird flu virus from infected wild birds to poultry via the air is negligible.
Specifically, the risk of introduction was investigated from volatile wild waterfowl manure in the vicinity of the poultry house during the bird flu period from October to March. But also produced from an aerosol, by exhaling or spitting bird flu-infected wild waterfowl that could enter the poultry house via the air inlet.
As a precaution, it is important that carcasses of dead wild birds infected with highly pathogenic avian flu are removed from the natural environment as soon as possible after death. They could be the source of loose feathers released when scavengers eat the carcasses. Feathers of highly pathogenic bird flu-infected dead wild birds contain bird flu virus, which can survive for a long time in the feathers.
Wild waterfowl such as ducks, geese, swans and gulls are the natural reservoir of bird flu viruses. These wild waterfowl can play an important role in introducing the virus into poultry, as they shed bird flu virus when infected.
Feces of avian flu-infected wild birds deposited in the vicinity of poultry houses can be taken into the poultry house. For example, because it can attach to boots, clothes, tools, it can get into the house with bedding material stored outside the house, or because it can be taken into the poultry house by the fur or paws of rats and mice.
In addition, there are indications from previous experience that the bird flu virus can be transferred via the air from farm to farm if it is produced in large quantities by large numbers of infected chickens in a house. It has now been investigated whether transmission of the bird flu virus by infected wild birds from the environment outside the house to the house is a risk.
The focus of this risk assessment for transmission from a highly pathogenic avian influenza virus contaminated airborne or aerosolized wild waterfowl feces was chosen because of the potential risk reduction of these transmission routes through the application of windbreak mesh.
All relevant building blocks for conducting a semi-quantitative risk analysis have been listed for the study. A field-experimental study was also carried out into the possibility of bird manure evaporating during the risk period for bird flu.
More information can be found in the report ‘Environmental airborne transmission of avian influenza virus via wild waterfowl to commercially reared poultry‘.
Copyright ©2021 AgriHolland B.V.
–
