Fresno County health officials said Wednesday that four more people have died of flu-related complications, making this virus the most deadly in five years.
"Right now, we're already at 11 deaths and we're not even through the full flu season," said Joe Prado, manager of community health at the Fresno County Department of Public Health.
Flu season typically runs from the end of September through the end of May. Fresno County recorded a total of nine flu-related deaths in the 2012-13 season, five in 2011-12, three in 2010-11 and seven in 2009-10, Prado said.
Meanwhile, Madera County health officials said Wednesday a 61-year-old woman is the second person to die of flu-related complications. The county reported its first flu death Tuesday, that of a 63-year-old woman.
The deaths reported Wednesday bring to 20 the number of people who have died in the central San Joaquin Valley so far this flu season. Kings and Merced counties have had three deaths each and Tulare County has had one.
California has required hospitals to report influenza-related deaths of people 64 years of age and younger for the past five years. This flu season, the victims in the Valley have been adults -- and all but one has been associated with H1N1, a novel influenza A virus that first appeared in 2009 and is also known as swine flu. One of the Fresno County deaths reported Wednesday was from an H3 influenza A strain that also is circulating in the community.
But it's the H1N1 strain that "tends to cause more severe illness to the younger (adult) population in their 50s, 40s, 30s, 20s," said David Luchini, assistant director of the Fresno County Department of Public Health.
Of the three H1N1 deaths reported Wednesday, two were women in their 30s and one was a man in his early 60s. The H3 death was a woman in her 50s.
It's unknown why the H1N1 virus attacks younger adults, but Luchini said the information collected from the hospitals "hopefully will help develop a better theory of what is triggering this."
This season, the majority of the patients who have died had health problems that put them at higher risk for complications from the flu, Prado said.
People with diabetes, high blood pressure, heart disease, obesity, smokers and those with weakened immune systems are at higher risk of flu-related problems, he said. Pregnant women also are at increased risk. If they have flu symptoms, they should see doctors for anti-viral medications, he said.
This year's flu vaccine provides protection against H1N1 and H3 strains, but most of the patients who died apparently had not gotten flu shots, Prado said.
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