A middle-aged man infected with the A/H1N1 flu virus has died in California's Contra Costa County, marking the second death in the county and the fourth in the San Francisco Bay Area, local health officials said on Wednesday.

"We are saddened by this man's death," Contra Costa Public Health Director Wendel Brunner said in a statement, noting that the victim had no other identified major health conditions.

"His death reminds us that even though most of the A/H1N1 cases in Contra Costa and the state have been mild or moderate, all flu viruses can be deadly and everyone should remain vigilant in helping to prevent the spread of A/H1N1 and seasonal flu," Brunner added.

Health officials said no connection has been found between the latest death and the county's first A/H1N1 flu-related victim, an elementary school child who died on May 29.

In addition to Contra Costa, two A/H1N1 flu deaths have also been confirmed in the area's Alameda County.

Including the four fatalities, eight A/H1N1 flu-related deaths have been reported so far in California, the most populous state in the United States.

"We anticipate that there will be more deaths throughout the United States and California before this outbreak ends," Brunner said.

(Xinhua News Agency June 18, 2009)