According to the Dutch Ministry of Economic Affairs, a poultry farm with 28,000 housed indoors was confirmed with an H5 strain of the bird flu virus on 30 November.

The farm is in the municipality of Zoeterwoude, which is in the province of South Holland (Zuid-Holland) in the west of the country. The birds had no outdoor access. The flock was culled on that day, overseen by the Dutch Food and Consumer Product Safety Authority (NVWA).

A surveillance zone was immediately set up within a 10-km radius around the farm. It covers four other poultry farms, which underwent testing.

Meanwhile, the investigation has been completed into all the country's duck companies, following the earlier outbreaks in other Dutch farms with this species. No bird flu virus of the H5 type has been found at these companies.

On 1 December, the Ministry confirmed that the virus affecting the birds in Zoeterwoude is the highly pathogenic H5N8 variant.

Within one kilometre of the affected farm is another poultry farm. To prevent the spread of the virus, all 50,000 birds there will be culled.

Of the other three companies in the 10-kilometre surveillance zone, two have no poultry and the other one is under investigation.

On the same day, two samples from wild ducks (wigeon) near to the town of Kamerik in the district of Woerden (Utrecht province) have tested positive for the highly pathogenic H5 avian influenza virus, according to the Ministry.

The sampling is part of the investigation into the possible role of wild birds in the spread of bird flu in the Netherlands.

Secretary of Economic Affairs, Sharon Dijksma, has informed the Dutch parliament that an investigation by the Central Veterinary Institute (CVI) has revealed that the three earlier outbreaks of highly pathogenic bird flu cases in Hekendorp, Ter Aar and Kamperveen occurred independently.