The government said Monday that a man in Shizuoka Prefecture is infected with a dengue virus that has a different genetic sequence than the virus first detected in Japan in August.

The finding indicates that the new-type virus arrived in Japan via someone other than the person carrying the virus that infected several people through mosquitoes, mainly at Yoyogi Park in central Tokyo.

The man in his 20s was identified Sept. 18 as having developed a dengue symptom on Sept. 10. But the site of his infection has not been fixed as he said he visited Tokyo in early September and was bitten by a mosquito Sept. 9 or 10 in the eastern part of Shizuoka Prefecture.

The health ministry Monday reported that three more people have been identified as infected with the dengue virus, bringing the total in Japan to 150.

Before this outbreak, no infection in Japan had been found since 1945.