The death of a 23-year-old North Seattle man from acute respiratory failure was caused by a strain of hantavirus, which has been linked to several U.S. deaths - mostly in the Southwest - since 1993.

The man, whose name was not released by the Seattle-King County Health Department, died July 8. The cause was confirmed by Oregon State University and University of New Mexico laboratories on July 15, the department said in a Friday news release.

An investigation is under way to determine how the man was exposed to the disease. Previous infections have been linked to inhaled particles of deer-mouse waste.

There was no evidence of deer mice at the man’s home, the department said. Investigators are looking at sites he had visited in Eastern and Central Washington and in Montana.

His case is one of 14 reported in Washington state since 1985. Seven of those victims have died.

A total of 164 cases have been reported nationwide. About half of those patients also died.

Thirteen of the state victims were exposed in Washington. Deer mice have been trapped and tested in 13 counties, but none in King County. Fifty-eight of the 451 mice tested positive for the virus, a rate consistent with that found in other states, the health agency said.