Pertussis Snapshot​

The Pertussis Snapshot provides quarterly pertussis surveillance data from 2021-2026 in California. The case counts shown are preliminary and may change after final review.  Total counts for all figures and tables include cases for the entire year.  Refer to "About the Data" for more details about the pertussis case data presented in the dashboard. Data highlights are provided with the dashboard, and you can download the data as an Excel workbook for your own analysis.

About the Data (PDF)  | Download the Data (Excel)​​​

​Data Highlights

Between January 1 and June 30, 2026, there were 1,295 cases of pertussis reported in California compared to 1,543 cases in the same time period in 2025.  Of these, 40 cases (3%) were in infants under 4 months of age, a 46% decrease in this age group compared to quarter 2 in 2025. Among all cases under age 18, 40 were hospitalized, with 27 (68%) being unvaccinated. 

Elevated pertussis activity was observed in the South Bay Area, although the Bay Area region as a whole has not experienced an increase in pertussis cases with 450 cases being reported in the first quarter of 2026 as compared to 460 cases in the first quarter of 2025.