Simulated Infectious Disease Outbreak in California

Author

Group 8: Erin Curlee, Val Stacey, Ana Terzo

Published

November 11, 2025


Problem Statement

In the early spring of 2023, a novel infectious respiratory disease began spreading throughout California. Our team at the California Department of Public Health was asked to characterize the outbreak and identify areas and populations that are being impacted the most.

This report examines the progression of infections from May through December 2023, compares disease burden across counties and demographic groups, and develops an approach for prioritizing prevention and treatment resources based on available surveillance data. To address these objectives, we integrate weekly infection counts with county-level population estimates, including age- and race-specific distributions.

All data and statistics summarized in this report were compiled from three primary sources:

1. Statewide Weekly Infections by demographics for all counties except Los Angeles

2. Los Angeles Weekly Infections, provided separately from the state’s reporting system

3. County Population Estimates by race and age from the California Department of Finance


Our analysis centers on three primary questions:

  • How has the course of the outbreak evolved from May 2023 - December 2023?

  • Which geographic regions or demographic groups are experiencing disproportionately high burdens of disease?

  • How can we use the reported infection data to-date to develop priorities for allocating prevention and treatment resources?