A person who died last month was killed by the West Nile (search) virus — the first such fatality in California this year, Orange County health officials said Thursday.

It was the first known case of the infection in Orange County, said spokesman Howard Sutter. There have been more than 30 cases so far of West Nile statewide.

Tests confirmed the infection and cause of death Wednesday, Sutter said. No information about the victim's identity was released.