Welcome! My name is Tomás León. I’m currently the Decision Intelligence Chief at the California Department of Public Health (CDPH). I was hired in 2020 as the first formally trained infectious disease modeler on the only state health department modeling team in the United States. I was involved in many forecasting and analytics efforts for California’s COVID-19 response, including the Regional Stay at Home Order, variant nowcasting and scenario modeling, and surveillance-based analyses of post-vaccination and reinfection COVID-19 outcomes. I became Modeling Team Lead in 2021 and hired other infectious disease modelers who have done pioneering work at CDPH applying advanced methods including AI/ML. In my role, I interact directly with our leadership and policymakers and guide our team in developing evidence to inform their decision making. I support making data and models as publicly available as possible through our Open Data Portal and public-facing state modeling website CalCAT. I also work closely with our local health jurisdictions to meet their modeling needs and collaborate frequently with other states and academic partners. Our team’s portfolio continues to evolve, as we conduct modeling work on respiratory syncytial virus (RSV), West Nile virus, congenital syphilis, and hepatitis C.
I was formerly a GIS lecturer in the UC-Berkeley Online MPH program and a postdoc at UC-Berkeley in the Marshall Lab focused on disease ecology, specifically the fine-scale movement of Aedes aegypti and Anopheles gambiae s.l. mosquitoes and the impacts of the environment on their population dynamics. I worked with the MGDrivE team on incorporating seasonality and ecological considerations into that model for field sites with the UC-Irvine Malaria Initiative.
Previously, I did my PhD in Environmental Health Sciences under Robert C. Spear, who spent most of his recent career on schistosomiasis. I adapted and expanded his environmental determinants of transmission approach to the cases of opisthorchiasis (liver flukes) in northeast Thailand and clonorchiasis in southeast China, incorporating hydrologic models into infectious disease transmission models. In the course of this research, I spent a memorable year in Thailand for a Fulbright looking at the impacts of local aquaculture on parasite transmission.
My academic background
- Ph.D. Environmental Health Sciences, UC-Berkeley, 2018
- Designated Emphasis in Development Engineering
- M.S. Global Health & Environment, UC-Berkeley, 2014
- B.S. Environmental Engineering, Georgia Tech, 2012
- Minor in Sociology
Feel free to email me for more information. A copy of my resume is available here.