Thank you for helping us better understand the spread of COVID-19 in our community!

Enrollment in the CATCH Study is currently closed.

A sincere THANK YOU to all of the participants who have joined the CATCH Study since its inception in October 2020 through the initial pilot phase to help us better understand the distribution and prevalence of COVID-19 in our communities.

Study Overview and Demographics of CATCH Study Participants

From across the 12 counties of the greater San Francisco Bay Area, over 14,000 participants enrolled in the study, with ~30% reporting their daily symptoms and exposures on a regular basis. See below a distribution of the participants by city, age & gender.

As positivity rates rose throughout our community and the world, so has the positivity rate in the CATCH Study. Between December 1, 2020 and January 11, 2021 (the post-holiday gathering period), the study team saw an increase in positive cases. As this occurred, we added parallel efforts in working with public health and community organizations that served those of greatest need. In particular, we had successful collaborations in both Santa Clara and Napa County, which experienced increased positivity as we entered the purple tier. Through these collaborations, we increased participant enrollments and testing in these communities, allowing the study to catch several cases early on and collect valuable data on exposures and symptoms.

Enrollment and further data collection are currently closed. With COVID-19 cases surging throughout our community and the world, contribution to this important research has provided much needed information and helped to better understand the epidemiology of the disease. Our team is hard at work on several analyses and are preparing for important publications. We hope to share this information as soon as they become available with all our participants in the near future, and also hope to invite you to participate in a future phase of the CATCH Study.

If you are new to the CATCH Study, sign up for updates.

Again, we would like to extend a “THANK YOU” to all our participants and public health community outreach teams for your contribution towards this important research. We are still in the midst of a surge in our community and it is more important than ever that we all take the necessary precautions to protect ourselves and our community. Please continue to follow CDC guidelines by wearing a mask, washing your hands frequently, and avoiding large gatherings. Should you have the need to be tested, here are several online resources for locating a testing center near you:

Stay safe,
Co-Principal Investigators, Study Director & the entire CATCH Study Team

Lorene Nelson, PhD
Associate Professor
Epidemiology & Population Health
Stanford University
Dr. Yvonne Maldonado
Professor of Pediatrics
(Infectious Diseases)
Epidemiology & Population Health
Stanford University
Dr. Stephen Quake
Professor of Bioengineering, Stanford University; Co-President, Chan Zuckerberg Biohub
Chan Zuckerberg Biohub
Pat Arensdorf
CATCH Study Director
Vera Program Lead
Chan Zuckerberg Biohub
CATCH Study Core Team
  • Alyssa Hayashi
  • Andy Martin
  • Barbara Topol
  • Jessica Hinman
  • Kimberly Chau
  • Jae Lee
  • Nelson Lee
  • Thomas Quarre
  • Trent Buskirk
  • Winnie Subramaniam
  • Jeff Raikes
  • Kartik Raghavan