More dead swans have been pulled from the waters of the Baltic Sea. They are apparent victims of bird flu. Ten new cases have been discovered in northern Germany, while two more were detected in Greece and another one in Austria. Some experts believe the most deadly strain of the virus, H5N1, has been in northern Europe for several weeks.“There can only be one response to this very serious situation,” said the German Agriculture Minister Horst Seehofer. “To combat this animal disease rigorously and forcefully, always keeping people’s safety in mind as the top priority.” Countries across western Europe are introducing measures to stop H5N1 spreading to poultry farms. The French have ordered all birds to be vaccinated or kept inside. Experts say quick culling is the best way to contain an outbreak. “We are applying the principle of precaution,” said French Agriculture Minister Dominique Bussereau. “I think that those in the business understand perfectly that these measures are in their interests, regarding consumers.” Those buyers are already voting with their wallets, with sales of poultry products plummeting. A total of 91 people have died from bird flu worldwide. There are fears the virus could mutate into a strain that passes easily from human to human.