Valley Fever, caused by the soil-dwelling fungi Coccidioides immitis and posadasii, is a growing public health concern in the U.S. Southwest, particularly in rural and underserved communities. Spread by inhaling fungal spores from disturbed soil, the disease can cause severe respiratory illness and even life-threatening complications, especially among vulnerable populations. Climate change and environmental disruption are expanding the fungus’s reach, yet surveillance tools remain limited.

This project pioneers the use of wastewater-based epidemiology to detect Coccidioides as a population-level signal of infection risk. Building on successful environmental monitoring systems developed during COVID-19, the team will validate a new method for measuring fungal DNA in wastewater samples collected during California’s 2023-2024 Valley Fever surge. By comparing these levels with reported case data, climate trends, and socioeconomic vulnerability indicators, the researchers aim to create an early warning system for future outbreaks.

This innovative approach has the potential to transform how Valley Fever and other environmentally driven diseases are tracked and managed. In doing so, the project lays the groundwork for more equitable public health responses in communities disproportionately affected by climate-sensitive diseases.

“Wastewater-based epidemiology provides an opportunity to agnostically identify clinical, subclinical, and asymptomatic infections, so that we can understand how and where the Coccidioides fungus is spreading,” says Rebecca Linfield, MD, MS, a postdoctoral fellow and a principal investigator on the project. “Ultimately, we hope that wastewater monitoring of Coccidioides can provide an early warning signal regarding rising cases to underserved communities.”

Co-Principal Investigators:

Rebecca Linfield, MD, MS – Post-doctoral Fellow, Department of Infectious Diseases, Stanford University School of Medicine

Alessandro Zulli, PhD – Post-doctoral Fellow, Civil and Environmental Engineering, Stanford University School of Medicine

Julie Parsonnet, MD – Professor, Medicine and Epidemiology & Population Health, Stanford University School of Medicine

Alexandria Boehm, PhD – Professor, Civil and Environmental Engineering, Stanford University

Funder:

Stanford Center for Human and Planetary Health