Flu activity ramping up in Sonoma County, widespread in state

This flu season is shaping up to be a really bad one, equal to or worse than the last one and driven by a viral strain that genetically altered after the latest vaccine in use was developed, local health officials said.

The flu is widespread throughout the state, health authorities said this week, and the number of cases is very high. In Sonoma County, flu incidence is moderate but rising quickly.

“There have been four outbreaks in residential care facilities and one severe case of the flu countywide,” said Dr. Karen Holbrook, the county’s deputy health officer.

A severe case of the flu is defined as one where a patient 65 and under tests positive for the influenza virus and is admitted into an intensive care unit because of the severity of their illness, Holbrook said.

State health officials said Friday that 27 people younger than 65 have died of the flu in California since October, compared with three at the same time last year. Nationwide and in California, flu activity spiked sharply in late December and continues to grow.

Dr. Gary Green, head of infectious disease at Kaiser Santa Rosa Medical Center, described the developing flu season as “pretty severe and very active.”

“We’ve seen an early sharp rise in flu activity but it has not peaked yet,” Green said.

Green said that ?49 percent of all tests for the flu this week have come back positive.

“That’s a big number,” he said.

The Kaiser hospital in Santa Rosa, Sonoma County’s largest hospital, has seen “record numbers” of patients with flu-like symptoms in the emergency department.

“Last year, the flu was so bad that hospitals were beyond surge capacity,” Green said. “We’re not at that level yet. We’re having bad back-to-back flu years.”

This season, the majority of influenza specimens have been typed as H3N2 influenza A, a strain that can cause more severe illness and lead to more hospitalizations and death in people 65 and older and younger children, health officials said.

Influenza vaccine in general is less effective against H3N2 viruses. But Green and Holbrook stressed that the vaccine does provide some protection, and could result in more moderate illness if a person does get the flu.

On Thursday afternoon, Marcie Swan, 47, of Rohnert Park sat in the vaccination clinic of Kaiser’s Medical Office ?Building 4 on Old Redwood Highway in north Santa Rosa. Swan, a floor manager for a local Safeway grocery store, said she started getting the flu shot again two years ago. She got sick that year, but her symptoms were mild.

“I have heard the vaccine isn’t perfect, so I was hesitating,” she said. “I got the flu shot again last year, but I didn’t get sick.”

Green said the influenza virus has three or four components. He said vaccine concocted in the past few years has been two parts influenza A and two parts influenza B, known as the “quad vaccine.” He said scientists correctly identified the right H3N2 strain, but it “drifted” or changed while the vaccine was being processed in egg cultures, thereby reducing its effectiveness against the flu virus in circulation.

“This strain can be more severe and it’s harder to manufacture because it seems to mutate,” Green said. “The ?A component is a weak match and the B component is a good match. … It’s better to have some protection than none.”

Green and Holbrook said people should not be discouraged from getting the vaccine, even if it is not perfect. They emphasized that a healthy person who gets a mild case of the flu is less likely to spread the illness to others who are more likely to become severely ill, such as seniors, infants or those with compromised immune systems.

“It doesn’t just protect you. Your protection protects others,” Green said. “If you don’t get the flu or a mild or brief case, you’re less likely to transmit it to someone else. It lowers the transmission risk.”

Health officials said people who come down with flu-like symptoms, including fever, should not go to work or school.

Holbrook said it’s not too late to get the vaccine, which usually takes two weeks to become fully effective.

“We’re expecting the flu to peak in the near future, but even thereafter that it could last for weeks and weeks and could extend all the way into the spring,” Holbrook said.

Holbrook said those with flu symptoms should stay home until 24 hours after a fever is gone.

“Cover your nose and mouth when you cough or sneeze, wash your hands often and avoid touching your eyes, nose or mouth,” she said.

Those who are at high risk of severe illness should contact their medical providers immediately, she said. Antiviral flu medicine can also reduce the severity and duration of the illness, Holbrook said.

Last flu season, from October and to spring, there were 12 outbreaks and six severe cases in Sonoma County, officials said.

This article includes information from the Los Angeles Times. You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @renofish.