A 45-year-old man of Shijonawate, Osaka Prefecture, who had contracted the new type of influenza, died Wednesday, according to the Osaka prefectural government.
Although the cause of death has not yet been identified, the case brought the toll to 12 deaths in Japan related to the new H1N1 strain of influenza, including suspected cases. It was the first new-flu related death in the prefecture.
It is also the nation's first case in which a person who had never suffered major or chronic diseases had possibly died from causes related to the flu. However, the government said it was unlikely the flu was the cause of death as his condition had improved.
According to the prefectural government, the man was found to have contracted influenza A in simple testing on Monday at a medical institute where he was being treated for a continuous mild fever.