Valley fever spreads beyond endemic regions

October 2021-May 2022

Gathering molecular data from soil collected at various field sites in the Southwest U.S and creating an ecological niche model to map the current and future spread of Valley fever in the U.S. In addition, researching the effects of restoration using biological soil crusts on airborne spores of Valley fever.

Pathogen and Microbiome Institute, Barker Laboratory
https://www.bridgetbarker.com/

Southwest Health Equity Research Collaborative (SHERC)

NAU Researchers Recieve SHERC Funding

Fairness First

Valley fever is a fungal infection that is caused by Coccidioides immitis and Coccidioides posadasii. Infection occurs when mammals inhale airborne spores that are discharged from soil. Valley fever is thought to be endemic to the Southwestern United States, but in the past decade, the range of Valley fever has been suspected to have increased. Climate change has been implicated in this range expansion from hyper-endemic regions such as Southern Arizona to Northern Arizona. Climate fluctuations associated with the spread of Valley fever are higher temperatures, lower precipitation, and drier soils. Due to this reemergence, there is an urgent need to understand the ecological niche and determine the extent of the spread of Coccidioides spp. in the Southwestern United States. Our objective is to determine the extent of the spread of Valley fever due to climate fluctuations. We took eight years of environmental surveillance data from various sites throughout Arizona that were confirmed positive through RT-qPCR analysis. Using this data, we also created an ecological niche model to predict the current and future range of Coccidioides spp. The results showed an increase in endemicity in Arizona. By 2070, the model shows Coccidioises spp. spreading throughout the Western United States. The knowledge gained from soil sampling and ecological niche modeling will lay the foundation to better understand disease surveillance and how global climate change will exacerbate this and other environmentally-acquired pathogens in the coming decades.