Climate Change Increases Frequency and Reach of Valley Fever

Climate Change Increases Frequency and Reach of Valley Fever

Once confined only to the Southwestern US, the disease Valley Fever is now spreading across the region. It is contracted by breathing in the fungal spores of Coccidioides, a fungus that lives in soil, which is more likely to happen when conditions are windy and dusty. In California, infection rates have increased by 800% since 2000, and researchers have found that climate change is the cause of the new spread. Worsening drought, extreme heat, and longer wildfire seasons establish the perfect conditions for creating and moving the dust.

According to the Los Angeles Times, when the soil dries and temperatures rise, the fungus breaks up into spores that can be launched into the air in billows of dust and by the end of the century, Valley Fever may be a threat across the entire Western US.

Medical Centric: Valley Fever, Causes, Signs and Symptoms, Diagnosis and Treatment, October 27, 2021.

Researchers project how valley fever will spread through the end of the 21st century in response to high climate warming. By 2095, much of the western U.S. could be considered endemic.(Morgan Gorris, Los Alamos National Laboratory (formerly UC Irvine)) | Los Angeles Times, April 4, 2022.

Why This Matters

Valley fever is just one example of how the climate crisis is and will continue to impact people. Rising cases are due to shifting weather patterns. California is currently experiencing its “driest two decades in 1,200 years.” These conditions are ideal for the fungus to spread quickly.

The projected spread of Valley Fever is due to general drought conditions and warming trends. According to a 2019 study, cases will increase by 50% across 17 states under a “high-warming scenario -- or one in which greenhouse gas emissions continue unabated.

CBS: Huge carbon emissions cuts needed, UN climate report finds, April 4, 2022.

PBS: Hot, Dry Winds Help Spread Deadly Valley Fever Infections, June 13, 2013.

Spreading Faster & Further

Climate change is causing the increased spread of diseases throughout the globe. Its resulting biodiversity loss, vector-borne illnesses, and shifting weather conditions are three major contributors to disease spread. According to a study on the impacts of biodiversity loss,“mounting evidence indicates that biodiversity loss frequently increases disease transmission.”

Changing weather patterns allow for the movement of pathogens, and warmer climates allow for some diseases to thrive where they once couldn’t. According to a study about vector-borne diseases, “by 2050, disease-carrying mosquitoes will ultimately reach 500 million more people than they do today, including some 55 million more Americans.”

“We’re on a very dangerous path right now, slow action on climate has made dramatic warming and large-scale environmental changes inevitable, and I think that increases in disease are going to come along with it,” said Scott Weaver, the director of the Institute for Human Infections and Immunity at the University of Texas Medical Branch in Galveston.

Conservation International: Biodiversity and Pandemics, September 23, 2021.

The Weather Network: How climate change can impact mosquito-borne diseases, May 27, 2020.