Hokkaido Prefecture announced that a man in his 70s in the southern part of the prefecture died from tick-borne encephalitis, the third case of tick virus infection in Japan and the second death.
The prefecture's public health division said Tuesday that the man became sick in mid-June, running a high fever and slipping in and out of consciousness. He checked into a hospital in the city of Hakodate but died earlier this month, according to the division.
No tick bites were found but a blood test confirmed his infection with a tick-borne virus. Officials said he could have been infected in the prefecture.
The tick-borne virus that causes encephalitis is known to exist in parts of Hokkaido. Two previous cases have occurred in the prefecture.
The officials said infection with the virus only takes place where the virus-carrying ticks live, noting that the virus is not transmitted from person to person.
A group of researchers at Hokkaido University in May said it has confirmed the virus infection among wild animals.
A prefectural official warned people to wear long-sleeved shirts and long pants when they hike in the mountains or are near bushes, and to seek medical help immediately if they are bitten.