"Since the beginning of this current flu season, there have been 18 people admitted to intensive care units in San Joaquin County with influenza," Dr. Karen Furst, the county's interim health officer, told FOX40.
This time last year, only eight people in the county were hospitalized with the flu.
While this flu season has hit harder than in the past, Furst says the same steps can be taken to avoid becoming sick.
"The most important thing people can do to prevent getting influenza is to get the flu vaccine. It is not too late to get vaccinated," she said.
Families are also encouraged to wash their hands and avoid touching their eyes and mouths.
If you're sick, it's best to stay home. Doctors recommend staying home at least 24 hours after your fever goes away.