The outbreak was discovered after sampling at a breeding facility with parent animals for broiler chickens, according to the Norwegian Veterinary Institute (SVA).
The Swedish Agricultural Agency has decided to block off the farm and that nearly 22,000 animals are to be euthanized, the authority states in a press release. The buildings in question must then be cleaned up.
The virus in the current case is H5N1, a variant that has been circulating in Europe and Sweden since 2020.
“Despite occasional reports of cases in humans, the assessment by the European Disease Control Authority (ECDC) is still that the risk of infection to humans is generally low,” writes the Swedish Agency for Agriculture.
First of the season
The infection is suspected to have entered the facility through spread from wild birds. The outbreak is the first case of bird flu at a commercial facility this season, according to the agency.
“It has so far been a relatively quiet season for Sweden, but the danger is not over. Now that the migratory birds are coming back, it is especially important that you continue to be careful with your hygiene routines to avoid getting the infection into your animals,” says Katharina Gielen, head of infection control at the Swedish Agency for Agriculture in the press release.
Increased number of cases in Europe
In Europe, the number of cases in wild birds has increased in recent months. Laughing gulls have been particularly affected, according to the Norwegian Veterinary Medical Institute.
“SVA therefore assesses that in the coming weeks there is a risk of increased spread of infection in connection with the spring migration,” says Malin Grant, epidemiologist at SVA.
The virus is found, among other things, in the droppings of wild birds and can, for example, be spread further via car tires and shoes.