Bird flu illustration: Al-Jazeera photo

A new kind of bird flu hitting European poultry farms will surely continue to spread among birds, the World Health Organization said Tuesday, urging countries to be “vigilant”.

Whether the virus will spread to humans remains unclear, the UN health agency said. But in Egypt, three women have been killed by H5N1 bird flu after coming in contact with infected birds. One of the victims, a 19 year old woman died on Monday.

The second a 30-year-old woman from the province of Minya, south of Cairo died Tuesday, the Egypt health ministry said in a statement reported by Al-Ahram on its website. She died in a hospital in the southern city of Assiut

“We should all be quite vigilant,” Elizabeth Mumford, a scientist with the WHO’s Global Influenza Programme, told reporters in Geneva.

Responding to questions, she said she “absolutely” expected more bird flocks getting sick.

She stressed the importance of culling sick birds and monitoring fever in humans who have been in contact with sick birds to ensure any possible human infections are spotted.

Germany and the Netherlands have been confirmed to be dealing with the same subtype of a highly infectious strain of bird flu, called H5N8, which appears to be similar to a virus that has been infecting birds in China, Japan and South Korea since the beginning of the year, she said.

Britain has also been hit with “a highly pathogenic H5 outbreak also in poultry,” Mumford said. It was not yet confirmed, though, that it was the same H5N8 strain.

“It could be something else,” she said.

Some 150,000 hens at an egg farm near Utrecht in the Netherlands were set to be culled, while 6,000 ducks on a Yorkshire farm in Britain were also to be put down, authorities said.

WHO said the virus had most likely moved from Asia to Europe with migratory wild birds.

Several hundred thousand birds, mainly ducks, have been culled over the last two months because of a South Korean outbreak.

So far, no cases of human infection have been detected, either in Asia or in Europe, Mumford said. She acknowledged though that “influenza viruses are very unpredictable, and it’s very difficult to tell what a new virus will do”.

“I must say that we really know very little about this virus, and until we get some experience with it, it’s a bit wide open,” she said.

Since H5N8 seems to be spreading quickly among poultry, she told AFP she “we will probably see some human cases”.

But while some people may be infected by sick birds, she said so far it appeared unlikely that the virus would begin spreading between humans