California’s Department of Public Health says the flu killed 329 people under age 65 in the last flu season, from October 2017 to August 2018.
But that is likely only a small fraction of the total deaths in the nation’s most populous state because the department didn’t count the hundreds of deaths of people 65 and older. The state figure could account for just 1 in 10 flu deaths.
The federal government’s Centers for Disease Control and Prevention estimated that approximately 80,000 people in the U.S. died from complications from the flu during the 2017-18 flu season — the most since 1976. The vast majority of those who died — about 90 percent — were seniors, ages 65 and up, the agency estimates.
While the federal government uses mathematical modeling to estimate the number of flu deaths, California’s figures have been based on reports of individual deaths.
State officials said they haven’t counted flu deaths among seniors because, in part, health providers were not required to report them.
But this year the California Influenza Surveillance Program is changing how it tracks flu-related deaths. It will base its data on death certificates and count all people whose deaths were classified as flu-related, regardless of age.
The department acknowledged that its new system still will likely result in an undercount.
The flu, an upper respiratory illness caused by various strains of the influenza virus, can cause a high fever, cough, body aches and gastrointestinal distress. While most people recover within a few days, older people, children and people with compromised immune systems are more vulnerable. Complications from the flu can cause severe illness, hospitalization and death.
Though it was an undercount, California’s figure still shows just how deadly last year’s flu was: About three times the number of Californians died compared with the previous flu season, state data show.
This year, experts predict a more typical, but still deadly, flu season.
So far, the flu is “circulating at low levels” in California, but the percentage of lab-confirmed flu infections are on the rise, a sign that this flu season is gaining momentum, said Dr. James Watt, chief of the Division of Communicable Disease Control at the state Department of Public Health. Using its new methods, the public health department reports that five Californians have died from the flu since Oct. 1.
Last year’s flu season in California was dominated by the H2N3 strain of influenza, but Watt said the state is seeing more infections from the H1N1 strain this year. Based on previous seasons, years in which the H1N1 strain predominates tend to be less severe, he said.
Experts recommend getting a flu shot to reduce the chances of getting or spreading the virus. “The main thing is people should get vaccinated,” Watt said. “It’s not too late.”
But getting the vaccine isn’t a panacea. The flu vaccine developed every year tends to have 40 to 60 percent effectiveness, so even those who receive the vaccine still might succumb. “If people get sick, they should stay home and not share their virus with friends and co-workers,” Watt warned.