Wild ducks are carrying bird flu but other migratory birds could also have the virus, according to researchers from the Erasmus medical centre in Rotterdam.

Excrement from two wigeons, a variety of wild duck, was tested for the virus at the Netherlands ecology institute and found to have the highly-infectious H5 variant of avian flu. It is not yet known if it is the same N type as the virus found in the five outbreaks recorded in the Netherlands over the past two weeks, Trouw reports.

‘We now know that these wigeons carry the avian flu virus, but there could also be other kinds of migratory birds which are infected,’ virologist Ron Fouchier told broadcaster Nos.

It is not clear how the virus was transferred to chickens kept in sheds but Fouchier says it is possible that wigeon droppings were carried from fields into the sheds on the shoes of farmers.

The most recent outbreak in the Netherlands was discovered on Sunday at a chicken farm in Zoeterwoude.

Researcher Henk van der Jeugd told Nos radio that the intensive poultry sector will remain vulnerable to bird flu. ‘We need to think about how we will deal with it in the future because it will keep coming back,’ he said.

Approach

Meanwhile, poultry sector organisation Nepluvi said on Tuesday that now it appears wild duck are to blame for spreading the disease, the government needs to change its approach.

In particular, the rules on moving poultry and eggs should be relaxed in areas without large expanses of water where wild ducks congregate, the organisation said.

Sector representatives are due to discuss the economic impact of the recent bird flu outbreak with government officials later on Tuesday.