YSPH Climate Change and Health Seminar with Dr. Jennifer Head, "The role of climate change, wildfire, and rodents in the emergence of Valley fever in California"

Valley fever is an emerging fungal infection caused by inhalation of the spores of Coccidioides spp. Since 2000, California has seen over 9-fold increase in the incidence of Valley fever, with 2023 reporting more cases than any other year on record. Access to moisture and nutrients is thought to support the growth of Coccidioides in soils, while soil disturbance activities and wind erosion may aid the aerosolization and transport of spores. The fungus contains genes associated with the breakdown of animal protein, giving rise to the hypothesis that rodent hosts serve as key nutrient sources. In this talk, I will provide evidence that swings between extreme drought and extreme precipitation are amplifying incidence in California. I will examine work to uncover the role that wildfires play in dispersion of spores, using both quasi-experimental study and ongoing efforts to detect the fungus in the air using unmanned aircraft systems. Finally, I will discuss findings from an ongoing longitudinal experimental field study seeking to understand the role of small mammals and their burrows in determining where Coccidioides is in the soil. I will conclude with thoughts on how climate change may be increasing the transmission of other environmentally-transmitted fungal pathogens, including those endemic to the eastern United States.

Jennifer Head is an Assistant Professor in the Epidemiology Department and a member of the Institute for Global Change Biology. Her research applies mathematical and statistical models to understand the impact of climate variation, environmental disturbances, and zoonotic hosts on infectious disease dynamics. A major focus of her work is on the emergence of environmentally acquired fungal infections, such as Valley fever. Her work combines methods from epidemiology, data science, econometrics, environmental health, and ecology. She collaborates closely with state and federal agencies to help convey findings into actionable public health outcomes.