Greece confirms first H1N1 flu case

(adds confirmation, quotes, details)

ATHENS, May 18 (Reuters) - Greece confirmed its first case of H1N1 flu on Monday, a student who returned from the United States at the weekend.

Deputy Health Minister George Papageorgiou told a news conference initial tests confirmed the 19-year-old had the virus, adding: "This is not a heavy case, he is in very good condition."

The student felt the first symptoms on Sunday and was now in hospital where he would be put in isolation room, he said.

Papageorgiou added that members of the student's family were being tested.

The World Health Organisation said on Monday the H1N1 flu strain, also known as swine flu, was spreading fast in Japan and the world might be seeing an influenza pandemic unfold.

It has confirmed the virus, a mix of swine, human and avian viruses, in 40 countries.

The Greek Health Ministry has said the country has enough "strategic stocks" of Tamiflu and other antivirus medicine to treat 12 percent of the country's 11 million population. Two hospitals in Athens were equipped to treat swine flu patients. (Reporting by Lefteris Papadimas, Renee Maltezou and Harry Papachristou; Writing by Ingrid Melander; editing by Andrew Dobbie)