The number of flu deaths in California surged to 97 among people younger than 65 in the third week of 2018, according to a report Friday from the state Department of Public Health, and that figure is particularly grim in light of flu death tolls from prior years.
Last season, the state reported 95 flu-related fatalities for individuals younger than 65; in 2015-16, 144; and in 2014-15, 78. Epidemiologists say that, even though people may have some immunity to the H3 strain of influenza going around the nation, it still can be particularly nasty and difficult to beat.
Public health officials urged everyone to get the flu shot. This year, though, people are complaining that they got immunized but came down with the flu anyway. Dr. Christian Sandrock, an infectious disease expert at UC Davis Health, said researchers are beginning to understand why.
“When the World Health Organization decided – and they do this every March or April – on which virus to include in the vaccine, they actually picked correctly,” Sandrock said, “but when the vaccine was made – it’s actually grown on eggs – and … during that period of growth, it actually mutated.”
Despite the mutation, Sandrock said, the vaccine can still be an effective flu deterrent, especially when paired with hygienic practices. People should wash their hands often, cover their mouths when coughing or sneezing, and stay home for at least two days after all flu symptoms are gone.
“Even though the shot may have a 20 or 30 percent efficacy, which is kind of what we’re thinking, that level of efficacy still can provide some protection,” Sandrock said, “and it may be just enough protection between getting a severe bacterial protection or not. It might be that you still come down with the flu, but your ability to handle that bacterial infection is better.”
The number of people suffering with this year’s H3N2 strain of the flu at home and in hospitals is above expected levels throughout the state, public health officials said, and they stressed that it is still not too late to get vaccinated since peak flu season typically occurs later in the year.
For the first time, the report from the public health department included fatalities by region. While the Bay Area and lower southern regions of the state reported the highest death tolls – 20 and 32 respectively – the Central Valley region had the highest rate of fatalities, 4.2 deaths per every million residents.
For public health purposes, the Central Valley region comprises Calaveras, Fresno, Inyo, Kings, Mono, Madera, Mariposa, Merced, Monterey, San Benito, San Joaquin, Stanislaus, Tulare and Tuolumne counties.
That region is so broad, said Dr. Karen Furst, the health officer for San Joaquin County, that it would take some study to determine what is driving the high rate of flu deaths. However, in San Joaquin County, she said, flu has historically been a problem. There are high rates of heart disease there, she said, and that puts people at higher risk for flu and pneumonia even if they are vaccinated.
Flu has not yet hit Sacramento County as hard as the Bay Area and Southern California. Still, the northern region, which includes Sacramento County and almost everything north of it, saw 3.4 fatalities per million people.
The rate of death in Imperial, Orange, Riverside, San Diego and San Bernardino counties was 2.8 per million. The Bay Area saw 2.5 fatalities per 1 million. The lowest rates of fatalities came in the upper southern region – Kern, Los Angeles, San Luis Obispo, Santa Barbara and Ventura counties – where 1.2 people died per million.
At UC Davis Health in Sacramento, hospital leaders have prepared an overflow room to handle a rapid increase in flu cases, but so far, they said it has not been needed. Nationally, officials say this year’s flu season is shaping up to be one of the worst since the 2009-10 swine flu pandemic, and cases of the virus are widespread in every state except Hawaii.