French authorities vowed to spare no effort in containing avian influenza. France is Europe's top producer and the world's fourth-largest exporter of poultry.
France confirmed late Saturday that H5N1, which can kill people as well as birds, had been identified in a wild duck found dead in the central-eastern Ain department.
While no human infections have been reported in Europe, just over 90 people have died from the H5N1 strain in China, Southeast Asia, Iraq and eastern Turkey since 2003.
At this stage the virus cannot be passed between humans, but experts fear that it could only be a matter of time before it can.
They say H5N1 could cause a pandemic with casualties running into the millions.
French Health Minister Xavier Bertrand stressed that the dead duck was an isolated case and that no poultry or humans had been affected.
However, food authorities said tests were continuing on around 15 birds found dead in various parts of the country.
"There will be no financial or economic obstacle in preparing France in the face of these risks," he said on Europe 1 radio, as the country's main farmers' union called for more state help in tackling the threat.
Bird sales plummet
The plight of EU poultry producers, faced with plummetting sales, will be discussed by agriculture ministers on Monday. Sales are down by 70 percent in Italy, 40 to 50 percent in Greece and 15 percent in France.
But in Brussels officials held out little hope in the short term.
"We're sympathetic but there is very little we, from the European budget, can actually do," a European Commission spokesman said.
The other EU member states so far to have detected the H5N1 virus are Austria, Germany, Greece, Italy and Slovenia. There have also been cases in Bulgaria, Croatia, Romania, Ukraine and Russia.
Italian health authorities said Sunday that H5N1 had been identified in a wild duck found dead in Umbria, in the centre of the country, bringing to 16 the total number of cases in Italy.
In Germany, Chancellor Angela Merkel on Sunday surveyed measures being taken to combat bird flu on the Baltic island of Ruegen, as army disinfection experts deployed to curb the spread of the virus.
Ms Merkel's visit came as 18 new cases of H5N1 were detected on Ruegen, bringing the country's total to 59.
Germany has begun enforcing an order to keep all poultry indoors, joining the Netherlands, Slovenia, Denmark, France, Greece, Luxembourg and Sweden in doing so.
Britain, too, said the risk of bird flu there was "more likely" following the French case.
"It's not inevitable, but it is clear, obviously, that it's more likely than it was when it was further away," Agriculture Minister Ben Bradshaw said.
Romania confirmed the presence of H5N1 in two villages on the shores of the Black Sea, bringing to 33 the number of sites where it has been found nationwide, a veterinary official said.
Nearly 35,000 birds will be culled, a top official for the Constanta region, Danut Culetu, told Mediafax news agency.
India death unfounded
In India, seven people were under observation while up to half a million birds were being slaughtered Sunday after the presence of H5N1 was confirmed.
But fears the virus caused the death of a farmer in the western Gujarat state proved unfounded. Authorities had earlier said he was a chicken farmer, but a health ministry official later revealed that he had not handled poultry.
In Nigeria, where there have been several major H5N1 outbreaks, UN health officials inspected an affected farm and assessed clean-up operations.
A team of World Health Organisation (WHO) experts went through the Bakabo Farm on the outskirts of the northern city of Kano with local monitors to check the health of farm workers.
Egypt, the second African country after Nigeria to report the presence of H5N1, said the virus was spreading.
Since it was first detected in three Egyptian governorates Thursday, H5N1 had been reported in at least six others. Most cases have been in small domestic coops rather than major industrial poultry farms, according to an official from the Supreme national committee to combat bird flu.
Bangladesh told its border guards to be extra vigilant to prevent the smuggling of live birds or poultry products from neighbouring India, a minister said.