University of Utah researchers collecting samples to map Valley fever’s spread through dirt spores

SALT LAKE CITY — A team of University of Utah researchers is studying a fungal respiratory infection that they believe is spreading through Utah soil and dust.

Researchers don’t yet know exactly which areas of the state are affected by valley fever, but epidemiology professor Katharine Walter said the fungus could spread further as the climate changes.

An interdisciplinary research team, including Walter, is trying to determine where the fungus that causes the disease can survive and where it might spread. The researchers received $375,000 for the Climate and Health Interdisciplinary Prize through the Burroughs Wellcome Fund to help fund their mushroom hunt and raise awareness for those at risk of infection.

Valley fever is difficult to track because the fungus that causes it does not spread from person to person. It grows stealthily in the ground but never emerges above the surface. Symptoms of the illness are similar to those seen with the flu and include fatigue, cough, fever, shortness of breath, headache, night sweats, muscle or joint pain, and rash on the upper body or legs, according to the Centers for Disease Control and Prevention.

In 2019, the CDC reported just over 20,000 confirmed cases of the disease, with very few in New Mexico and Utah.

“When most people think of mushrooms, they think of mold or mushrooms, something you can see,” Katrina Derieg said. Derieg is head of vertebrate collections at the Utah Museum of Natural History and a member of Walter’s research team.

“But it’s not a mushroom that has any sort of visible fruiting body. It can only be identified with a microscope, which makes it very difficult to identify in the field,” Derieg said.

Because valley fever is not well understood, it often goes undiagnosed or is misdiagnosed, which can delay necessary antifungal treatment for infected individuals.

According to a university release, 10 archaeologists working at a dig site in northeastern Utah fell ill with valley fever in 2001. Valley fever is typically found in warmer states and drier, and previous forecasts determined that the fungus would not survive in the soil in 2001. Utah, except for the southwest corner of the state, hundreds of miles from where the archaeologists.

“There have been incredibly intense temperature changes recently as well as precipitation and droughts here in the American West. All of this impacts the extent of where the fungus can exist,” Walter said.

Walter, Derieg, Eric Rickart, a biology professor at the University of Utah, and Kevin Perry, a professor of atmospheric sciences, collect soil and dust samples in various climate zones across the state. Samples will be tested for fungal DNA, and areas will also be searched for traces of fungus in rodents burrowing underground, as rodents are suspected of being a driving factor in the movement of the fungus.

The team is particularly focused on Washington and St. George County, as this is the area with the highest prevalence of Valley Fever. The university said rapid construction in the growing metropolitan area is generating potentially spore-laden dust in previously untouched areas of the Mojave Desert.

“Where others are considering future real estate developments, researchers see the potential for increased cases of disease,” the university said.

Washington County’s spectacular landscape and topography encompass a variety of microclimates that can stand in for various climates across the state. Samples from just the county can give scientists a relatively accurate picture of where the fungus is growing throughout the state.

By combining this information with predictions about how the climate will change over time, researchers hope to understand which areas are at risk now and in the future.

“An important part of this project is educating the public to let them know what is in their community, what signs they should look for and how they can prevent it,” Perry said.

Wearing dust masks on dry, windy days can help reduce the risk of airborne spores for people living in fungus-infested areas. Doctors who know the signs and symptoms of valley fever will be able to detect the disease early and administer appropriate treatments.

“Because we get sick by inhaling fungal spores found in the soil, people who work outdoors in jobs like construction, agriculture, and firefighting are at extremely high risk of infection and illness,” Walter said. “Valley fever is a growing health justice and environmental justice issue.”

Walter added that Valley fever is not the only disease that will evolve as the climate changes.

“This is just one example of an infection that will be, and already is, dramatically impacted by climate change. There are many others. And the consistent theme is always that the most vulnerable populations are the more at risk this problem really cannot be overstated,” Walter said. “Valley fever is just one part of this storm we are all experiencing.”