In connection with birds now starting to move to new areas, the spread of bird flu is expected to increase.
At the same time, the cold weather increases the virus’s chances of survival.
It warns both the Swedish Agricultural Agency and the Norwegian Veterinary Institute, SVA, for
– It is important to stay one step ahead and remedy any weak points in infection control, says Malin Grant, epidemiologist at the Norwegian Veterinary Institute, SVA.
No cases of infection have been detected in Sweden since the beginning of September. But the cold weather now increases the virus’s chances of survival and the risk of the infection spreading from wild birds to domestic birds.
– We have seen that this is a critical time of the year. There are several things that contribute to the fact that the risks may increase. It is partly because migratory birds carry the virus with them. Then we also have migratory birds that can gather in large flocks where the spread of infection increases, says Malin Grant, epidemiologist at the Norwegian Veterinary Institute, SVA.
The avian influenza virus has circulated among wild birds in all seasons in Europe. But it is more recently that the spread has been seen in connection with migratory birds arriving in Europe during the autumn.
Urges dog owners
At its worst, it was during the 2020–2021 season – when over 1.3 million poultry were killed in southern Sweden. And although it is a very bird-friendly virus, it can spread to other animals such as dogs and cats.
Several deaths of cats have been registered in Poland and the EU has previously urged cat and dog owners to keep their animals inside or on a leash in affected areas – also in Sweden.
– Over the past year, we have seen that there have been a lot of other reports of cases of bird flu in mammals as well. In Sweden, we have had several cases of wild foxes. We think it is unusual, but we urge dog owners to make sure that the animal does not come into contact with sick or dead birds, says Malin Grant.
WHO warns: The virus can adapt
At the same time, the WHO warns that the virus risks adapting and developing into new viruses that become more harmful to animals and humans.
“The increasing number of detections of H5N1 among mammals, which are biologically closer to humans than birds, raises concerns that the virus may adapt to infect humans more easily,” the organization writes in a press release.
The risk of the current type of bird flu infecting humans is assessed as very low by the Public Health Agency and the European Center for Disease Control ECDC. In 25 years, approximately 1,000 people have been infected, 500 of them have died.
– There are no signs that it is contagious from person to person. But the longer it is allowed to circulate among people, the greater the risk of it becoming a future pandemic virus. It is a scenario that we absolutely do not want, says Björn Olsen, professor of infectious diseases at Uppsala University.