Several outbreaks of severe bird flu in Europe and Asia have been reported to the World Organization for Animal Health (OIE) in recent days, indicating that the virus is spreading rapidly once more.

Following earlier outbreaks that resulted in the slaughter of tens of millions of birds, the spread of highly pathogenic avian influenza, colloquially known as bird flu, has put the poultry sector on high alert. Outbreaks frequently result in trade restrictions.

Epidemiologists are also interested because the virus can be transmitted to people. So far this year, China has documented 21 human illnesses with the H5N6 subtype of avian influenza, more than in the entire year of 2020.

South Korea reported an outbreak at a farm of around 770,000 poultry in Chungcheongbuk-do, the OIE said on Monday, citing a report from the South Korean authorities. All animals were slaughtered.

Also in Asia, Japan reported its first outbreak of the 2021 winter season, at a poultry farm in the northeast of the country, the OIE said, confirming a statement last week by Japan’s agriculture ministry. The serotype in this outbreak was H5N8.

In Europe, Norway reported an H5N1 bird flu outbreak in the Rogaland region in a flock of 7,000 birds, the OIE said

Outbreaks generally occur in the autumn, spread by migrating wild birds.

The Belgian government put the country on increased risk for bird flu, ordering poultry to be kept indoors as of Monday, after a highly pathogenic variant of bird flu was identified in a wild goose near Antwerp.

This followed a similar move in neighboring France earlier this month and in the Netherlands in October.

Bird flu cannot be transmitted through the eating of poultry products.