“There is a heightened risk,” Katharine Gielen of the Board of Agriculture told news agency TT.
The Board’s move is a precautionary measure and comes after a spate of outbreaks of the bird flu strain H5N8 in Germany, the Netherlands and the UK. The source of infection is unknown, but could be wild birds.
“We cannot rule out that it’s wild birds. They don’t always act predictably,” said Gielen.
The Board said that in cases where it is not possible to keep birds indoors, they should at least be penned in and should be fed and watered under a roof.
Asked how big the risk is that H5N8 will reach Sweden, Gielen said: “There is a heightened external risk because the source of contagion is unknown and because wild birds can carry this.”
The Board raised the alert level from one to two on its three-grade scale, a move welcomed by the Swedish Poultry Association. Its president, Charlotte Norrman-Oredsson, told TT: “Nobody keeps their birds outdoors now anyway so we feel safe. At the same time, it is good that they raise the bar.”
Out of Sweden’s 700,000 free-range chicken, 95 per cent are already kept indoors, according to Norrman-Oredson, who added that the risk would have been bigger in the summer when more birds are kept outdoors.
Tomas Borgström, a professor in clinical microbiology at the Sahlgrenska Academy, said the H5N8 strain, like the classic H5N1 bird flu, poses little danger to humans.
“If you are unlucky enough to catch the virus, you are in trouble, but it very rarely spreads to humans,” said Borgström.