BERLIN, Feb. 25 (Xinhuanet) -- The bird flu found in the center of Europe is the most virulent strain, German specialists said Saturday, fearing that the virus could have entered Europe last year.

    On Friday, it was announced that a dead duck found on Feb. 15 on Lake Constance in the Austrian and Swiss Alps had been infectedwith the deadliest strain, known as H5N1/Asia.

    Earlier this month, dead wild birds were found in northern Germany with the same illness.

    Scientists believe that the virus must have entered Germany last year rather than arrived with migratory birds this month, as the country is still in mid-winter and the dead duck was a type that lives on the shore of Lake Constance all year round.

    According to a spokeswoman at the Riems institute, H5N1 exists in several strains. A less pathogenic strain of H5N1 was found in 2004 in wild ducks in France and last year in ducks in northern Italy, she said.

    The deadliest strain claimed at least 90 human lives since it was first found in 2003. Enditem