The disease has been spreading along with migrating birds over the past few weeks, killing both wild birds and farmed poultry as far flung as Hungary, India and Iran.

The flu strain has now reached the Nordic countries. Sweden reported wild birds dead early last week, but at the end of the week the country reported an outbreak on a layer farm in the southern Skåne Län region. The outbreak was discovered after the animal keeper noticed an increased mortality, sick hens and hens with symptoms from the nervous system.

A protection zone (3 km) and a surveillance zone (10 km) have been put in place around the infected farm and the euthanising of animals has started, according to the Swedish authorities. Over 400 birds died in the outbreaks, but over 150,000 susceptible birds are likely to be destroyed in all.

Finland has also reported outbreaks in ducks found dead on the southern coast of the country.

France has reported its first outbreak of the H5N8 virus, in a group of waterfowl kept on a private body of water, in the town of Marck in the Pas-de-Calais region. These 25 ducks, and another batch of 35 ducks that also visited the water body, will be destroyed as a precaution. Unless there is another outbreak in poultry, France will regain its status as free from avian influenza on 3 December following the series of outbreaks at the end of 2015 and early 2016.

In the Netherlands, a duck fattening farm in Flevoland province has been infected, with 500 birds killed and another 9500 destroyed.

Meanwhile in Germany, another backyard holding has been infected with the virus, as well as a zoo and a large number of wild birds. The country's latest report to the World Organisation of Animal Health (OIE) also showed that the turkey farm where an outbreak was detected last week has now been depopulated.

Another avian flu outbreak has been reported in Iran on a layer farm, where 1401 birds died and another 25,472 had to be destroyed. This follows another outbreak in the same region, Tehran. However, the other affected country in the Middle East, Israel, has not reported any new outbreaks.

India published an official report on Friday detailing an outbreak in a Karnataka village that killed 900 birds and resulted in the destruction of 693 birds.

World Health Organisation information shows that no humans have yet been infected with the H5N8 virus, although some people have been infected with a related H5N6 virus in the past. Studies of previously isolated influenza A(H5N8) viruses have indicated that the virus does not transmit efficiently in ferrets, which is a model for influenza infections in humans.