This article was collaboratively produced by Grist and published alongside Arizona Luminaria. It is part of the Vital Signs series by Grist, which investigates the intersection of climate change and health, made possible through the support of the Wellcome Trust.
What is valley fever and how does it spread?
Valley fever is an infectious disease caused by a fungus that proliferates in the top layers of soil across parts of the Western United States. The illness is primarily transmitted when soil is disturbed, releasing fungal spores into the air. Both humans and various animals—including dogs, cats, sheep, and cattle—can suffer from this infection upon inhaling the spores. It is important to note that valley fever is not contagious and cannot be spread between individuals.
This fungal infection predominantly impacts the lungs, although it can disseminate to other areas in severe cases. While many individuals experience only mild symptoms or none at all, there are circumstances where valley fever can become life-threatening, necessitating hospitalization.
The heart of valley fever’s prevalence lies in the U.S. Southwest, particularly in regions like Arizona and Southern California. However, the fungus known as Coccidioides has been identified in areas extending as far north as Washington and throughout Central America and parts of South America. Recently, climate change has contributed to the expansion of the fungus into new territories in the Western U.S. by creating favorable growth conditions.
Who’s most at risk?
Individuals residing in, visiting, or working in areas where Coccidioides is present are at risk for valley fever. Those particularly engaged in agricultural, construction, or other outdoor occupations involving soil disturbance are in a higher risk category.
Additionally, certain groups are more susceptible to developing severe cases of valley fever. These include men, individuals of African or Filipino descent, pregnant women in their third trimester, and those with compromised immune systems such as HIV/AIDS patients or cancer survivors.
How can you prevent valley fever infection?
Currently, there is no guaranteed way to prevent valley fever. However, wearing N95 masks in dusty environments where the fungus may thrive could mitigate risk. A vaccine for canine patients is anticipated to be available by late 2025, and research is actively underway for a human vaccine that is still in its early stages of development.
What are the symptoms of valley fever, and how is it diagnosed and treated?
Common symptoms of valley fever include fever, cough, chills, fatigue, night sweats, headaches, shortness of breath, joint and muscle pain, and rash. In more severe instances, the infection can spread beyond the lungs to other body parts, such as the skin, bones, joints, and brain.
Diagnosis typically involves a blood test, and imaging techniques can help assess the disease’s severity. Without the blood test, valley fever may be mistakenly diagnosed as other conditions like cancer or tuberculosis.
While many valley fever infections resolve independently, healthcare providers may prescribe antifungal medications that alleviate symptoms without eradicating the fungus. The body’s immune system plays a critical role in the recovery process, and doctors often recommend rest and a nutritious diet to support healing.
What’s being done to address valley fever?
Considerable efforts are underway to combat valley fever. The National Institutes of Health has allocated significant funding to researchers in multiple states to explore new antifungal therapies, develop rapid diagnostic tests, and investigate why certain individuals experience severe disease while others remain asymptomatic.
At Arizona’s Valley Fever Center for Excellence, seasoned experts collaborate with public health entities and local hospitals to expedite diagnoses for affected individuals. Furthermore, researchers from California and Arizona are creating a surveillance system that integrates real-time weather data and construction activity to better identify regions where individuals are at heightened risk of spore exposure.
In total, there are four distinct research initiatives focused on the creation of an effective vaccine. The vaccine that is most advanced in its development is being produced by Anivive Sciences, a pet pharmaceutical company, which has recently entered the first phase for potential human use.
