While the nation crumpled under waves of flu viruses this year, the Sacramento region fared far better, with only a mild increase over last year's influenza rate, county officials said Thursday.

Twenty people have died of the flu so far this year in Sacramento County, officials said Thursday.

Factor in three flu fatalities that occurred during the 2012 portion of the flu season, and Sacramento County experienced 23 deaths during one of the nation's most severe influenza seasons.

The figure represents a slight increase over the Sacramento region's previous-year death rate from flu viruses, said Cassius Lockett, chief epidemiologist for the county.

"We did have a moderate increase over the (2011-) 2012 season," Lockett said. "We peaked around January and February this year, and now we are starting to taper off."

Lockett said that counties are required to report to the state Department of Public Health only cases in which patients are under 65 years old.

By that measure, Sacramento County officially reported to the state just 10 of its 20 total cases because half of the fatalities were people over the age of 65.

Factoring in an age limit as the state requires can skew the true picture of the flu's impact in a county.

For example, San Diego County had a record 60 flu-related deaths this season, the Associated Press reported this week.

However, the great majority of those fatalities involved seniors or elderly people, leaving only 11 for San Diego County to officially report to the state.

Regardless, Lockett said, reportable cases of those who tested positive for flu viruses represent only a fraction of total cases because so many go untested.

Not counting the deaths, Sacramento County reported 48 cases of severe flu illness in 2013 and 27 cases of severe flu in the 2012 part of the season. All were for people under the age of 65. And the figures represented just a portion of all those who came down with the flu in Sacramento County, Lockett said.

Compared to the rest of the nation, "it has not been a horrible year," said Laura McCasland, spokeswoman for the Sacramento County public health office.

One reason may be that, with fair warning from national media reports, Californians flocked to doctors' offices, clinics and pharmacies for their flu shots this year.

Even now, it is not too late to get a flu shot, health experts say. Vaccinations are recommended for anyone over 6 months of age, especially people whose chronic conditions may leave their immune system vulnerable.

Meanwhile, risk of the flu spreading throughout the state of California has lessened since its peak.

The Centers for Disease Control and Prevention downgraded the state from the category of "widespread" flu risk to the milder ranking of "regional."

Symptoms of the flu include fatigue, body aches, sore throat, cough and headache.

Lockett said anyone with those symptoms should stay home and rest - with the exception of venturing out to seek health care - until 24 hours after feeling better.

"We want to limit exposure," he said, noting that people should continue frequently washing their hands and using an alcohol-based hand-sanitizer if soap and water aren't available.

Call The Bee's Cynthia H. Craft, (916) 321-1270. Follow her on Twitter @cynthiahcraft.

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