Valley fever, a lung infection caused by the fungus Coccidioides, is increasingly prevalent across California, with cases spreading beyond its traditional regions in the Central Valley and Central Coast to areas like the Bay Area. The California Department of Public Health (CDPH) reported over 5,300 cases in the first half of the year, including five cases linked to the Lightning in a Bottle music festival near Bakersfield, with three attendees requiring hospitalization.
The incidence of valley fever has surged dramatically over the past two decades, with the number of cases tripling between 2014 and 2018, and then tripling again from 2018 to 2022.
This rise represents an overall 800% increase, according to research funded by the National Institutes of Health. Experts attribute this growth to changing climate conditions, where cycles of wet weather followed by drought create ideal environments for the fungus to thrive.
Valley fever is caused by inhaling spores of the Coccidioides fungus, which lives in the soil in parts of California and the Southwestern U.S. When the soil is disturbed, such as during construction or outdoor activities, these spores can become airborne and inhaled, leading to infection. Although anyone can contract valley fever, those who live, work, or travel in areas with high rates of the disease, especially where soil is frequently disturbed, are at greater risk.
The disease is no longer confined to its namesake region, the San Joaquin Valley. Increasingly, cases are being reported across California, particularly in Central and Southern regions. Bay Area residents, especially those who travel to affected areas like Kern County, are at risk. The fungus can travel long distances in the air, sometimes hitching rides on wildfire smoke, further spreading the disease to previously unaffected areas.
Valley fever can be contracted at any time of the year, but the risk is higher in late summer and fall. Symptoms resemble those of pneumonia and include fatigue, cough, fever, headache, shortness of breath, night sweats, muscle or joint pain, and a rash. While most people recover without treatment, some may experience severe or prolonged illness, especially those with weakened immune systems or underlying health conditions.
Diagnosing valley fever can be challenging due to its long incubation period and symptoms that overlap with other illnesses, such as COVID-19. A blood or skin test is necessary to confirm the infection. Although the disease is not contagious, those who develop symptoms should seek medical advice, especially if symptoms persist for more than a week.
Treatment for valley fever typically involves a course of oral antifungal medication, especially for those at higher risk of severe disease. In rare cases, the infection can spread beyond the lungs to other parts of the body, such as the brain or bones, requiring more intensive treatment.
Certain groups are more vulnerable to severe valley fever, including older adults, Black or Filipino individuals, pregnant women, and people with compromised immune systems. Preventive measures, such as wearing N95 masks in dusty environments, using air filtration indoors, and avoiding outdoor activities that stir up soil, can help reduce the risk of infection.
While there is currently no vaccine for valley fever, ongoing research aims to develop one. Until then, people living in or traveling to areas where valley fever is common should take precautions to minimize their exposure to dust and soil that may contain the fungal spores.
