Five people in Orange County of California have died of the A/H1N1 flu, registering the highest number of any county in the state, health officials confirmed on Tuesday.

The first death from the flu was reported by Orange County's Health Care Agency (HCA) on June 8 and involved a middle-aged man who had pre-existing medical conditions, the Orange County Health Department said.

The counties with the next highest number of deaths are San Diego, with four, and Contra Costa and San Mateo, with three each.

As of today, there have been about two dozen deaths in California, according to the HCA.

Dr. Hildy Meyers, medical director of Communicable Disease Control and Epidemiology in Orange County, said in a report that the number of deaths by jurisdiction is too small -- five out of a population of 3 million -- to draw any statistically valid conclusions.

The HCA's Deanne Thompson said that among the five Orange County fatalities, the A/H1N1 infection was not necessarily the underlying cause of death, but a contributing factor.

Orange County is reporting 387 confirmed cases of H1N1, but Thompson said that is not a full picture because the county is only testing suspected cases in patients that required hospitalization, are in clusters or such places as jail and school facilities.

"We're seeing an unusually high level of influenza activity, and since we can't predict what is going to happen, its important to remain vigilant," she said. "Very little other influenza remains to be seen."

Two of the most important steps in avoiding infection are frequent hand-washing and staying home if one is sick, she said.

The symptoms of the A/H1N1 flu are similar to those of seasonal flu and include fever, sore throat, body aches, headache, chills and fatigue. Some people have reported diarrhea and vomiting, Thompson said.

The swine flu virus has caused nearly 34,000 reported illness in the United States, including at least 170 deaths, according to the federal Centers for Disease Control and Prevention.

(Xinhua News Agency July 8, 2009)