ATTENTION: For current influenza activity in California, please visit the California Department of Public Health Influenza Website.


What is it?

Influenza (flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness. Serious outcomes of flu infection can result in hospitalization or death. Some people, such as older people, young children, and people with certain health conditions, are at high risk of serious flu complications. The best way to prevent the flu is by getting vaccinated each year. Flu activity is widespread in California and most of the United States.



The time from when a person is exposed to flu virus and infected to when symptoms begin is about 1 to 4 days, with an average of about 2 days.

People who have the flu often feel some or all of these signs and symptoms that usually start suddenly, not gradually:

  • Fever* or feeling feverish/chills
  • Cough
  • Sore Throat
  • Running or Stuffy Nose
  • Muscle or Body Aches
  • Headaches
  • Fatigue (very tired)
  • Some people may have vomiting and diarrhea, though this is more common in young children than in adults.

 *It’s important to note that not everyone with flu will have a fever

How Flu Spreads (Transmission)

Most experts believe that flu viruses spread mainly by tiny droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby. Less often, a person might also get flu by touching a surface or object that has flu virus on it and then touching their own mouth, nose, or possibly their eyes.


The first and most important step in preventing flu is to get a flu vaccination each year. CDC also recommends everyday preventive actions (like staying away from people who are sick, covering coughs and sneezes and frequent handwashing) to help slow the spread of germs that cause respiratory (nose, throat, and lungs) illnesses, like flu.

Parents, download the CDC “The Flu: A Guide for Parents” HERE.


Where can I get a Flu Shot?

  • Vaccine Finder. Check in advance about cost and insurance coverage; influenza vaccine is typically covered by health insurance

  • Free County Flu Clinics: Yolo County Health & Human Services Agency offer free influenza vaccines to individuals 6months and up at our Monday Immunization Clinics. Please call ahead if you have questions about your eligibility. Click HERE for a calendar of times and locations. 

Free Flu Clinic in West Sacramento on January 19, 2018 from 3-7pm at the City Hall Galleria (1100 W. Capitol Ave, West Sacramento). For more information click HERE.

Treating Flu

Most people with the flu have mild illness and do not need medical care or antiviral drugs. If you get sick with flu symptoms, in most cases, you should stay home and avoid contact with other people except to get medical care.

If, however, you have symptoms of flu and are in a high risk group, or are very sick or worried about your illness, contact your health care provider (doctor, physician assistant, etc.).

If you get sick:

1. Take Antivirals Drugs, if prescribed by a doctor

2. Take everyday precautions to protect others while sick

  • While sick, limit contact with others as much as possible to keep from infecting them.
  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub.
  • Clean and disinfect surfaces and objects that may be contaminated with germs like the flu.

3. Stay home until you are better

  • If you are sick with flu-like illness, CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. Your fever should be gone without the use of fever-reducing medicine
  • See Other Important Information for People Who are Sick

For additional information regarding the Influenza and the 2017-2018 Influenza season, please visit the California Department of Public Health Influenza website.


Yolo County Health & Human Services Agency

Infectious Disease Unit

137 N. Cottonwood Street, Woodland, CA


Business Hours: Monday – Friday, 8:00am – 5:00pm

Main Line (530) 666-8645

Confidential Fax (530) 669-1549


After Business Hours (24/7), call (530) 321-3620


Yolo County Press Releases                          Health Alerts (CAHAN)

List of Reportable Diseases                           Report a Disease