Marin Flu Surveillance Data

Marin Influenza Surveillance

Marin County Department of Health and Human Services tracks influenza activity by analyzing laboratory testing data and visits to local emergency departments for influenza-like illness.  During the influenza season, we produce an influenza surveillance report that summarizes influenza activity in Marin County, California, and the United States.

Marin Influenza Activity:  2020-21 Influenza Season

The 2020/2021 influenza season ended on May 22, 2021. We will resume regular updates to the influenza surveillance page at the beginning of the 2021/2022 influenza season, October 2021. You can find additional information about respiratory illness and COVID-19 in Marin County here.

Influenza-like Illness Activity

Influenza-like illness (ILI) activity in Marin County was lower than previous years during the 2020-21 influenza season. See Figure 1 below.

Figure 1. Proportion of Visits due to ILI: Kaiser San Rafael, MarinHealth Medical Center, and Novato Community Hospital Emergency Departments, 2018-19, 2019-20, and 2020-21 Influenza Seasons



Influenza Testing

Figure 2. Influenza Tests in Marin County, 2020-21 Influenza Season



Respiratory Illness Data

Marin County is monitoring respiratory illness data for surges that may be related to COVID-19 or influenza. The graph below shows data on respiratory illness admissions to the emergency department over the last three years. See Figure 3 below.

Figure 3. Respiratory Illness Admissions to the Emergency Department



Influenza Related Deaths

There were no influenza-related deaths of older adults (>65 years old) in Marin County during the 2020-21 flu season.

Note: Marin County now includes number of influenza-related deaths in our influenza communications. This does not indicate an increase in deaths compared to previous flu seasons, but a change in reporting procedures.



Visit the California Department of Public Health's influenza website here for more information.


United States

For national influenza data, visit the Center for Disease Control and Prevention's influenza surveillance website here.

Influenza Surveillance Update Reports: 2019-2020 Influenza Season

Email Address:

Marin Surveillance Update Archive

Other Influenza Surveillance Resources

California Department of Public Health
Centers for Disease Control and Prevention
World Health Organization