CNN
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After nearly two dozen cases of valley fever were confirmed in California following a summer music festival, state health officials are warning of an increased risk of fungal infections in the late summer and early fall.
“We are preparing for a possible resurgence of valley fever cases in the coming months and want Californians to know the signs and symptoms for early detection,” said Dr. Tomás Aragon, California Surgeon General and State Public Health Officer. “If you have a persistent cough and fatigue, especially if you have been outdoors in the dusty air of the Central Valley and Central Coast regions, please contact your doctor for information about valley fever.”
According to the California Department of Public Health, humans and pets can become infected by inhaling bacteria spores in outdoor dust that contain the valley fever bacteria. The infection occurs primarily in the southwestern United States and parts of Washington state, according to the US Centers for Disease Control and Prevention.
Valley fever, also known as coccidioidomycosis, is not contagious and does not spread from person to person. Symptoms, which include coughing, chest pain, headache, and fatigue, take one to three weeks to appear. The illness can last for at least a month.
In rare cases, the infection can spread from the lungs to the brain, spinal cord, skin, bones, and joints, according to the CDC.
Healthcare professionals can test for the disease through a blood sample or skin test.
Cases are on the rise in California, with at least 9,000 cases reported statewide in 2023 and more than 5,000 preliminary cases in 2024 as of July 1, according to the state Department of Health.
More than 10 cases of Valley Fever were reported among people who attended or worked at the Lightning in a Bottle music festival in Kern County in May. Nineteen people fell ill with Valley Fever and eight were hospitalized, according to the California Department of Public Health.
“Possible causes of this recent increase include winter rains after several years of drought, increased soil disturbing activities (including construction) in high-risk areas, and increased disease awareness, testing, and reporting. Additionally, while most valley fever cases in California have been reported from the Central Valley and Central Coast regions, there has been an increase in cases outside of these regions, including the northern Central Valley and Southern California,” the health department said in a statement.
A recent study published in the journal The Lancet Regional Health, Americas suggests that climate change may affect infection rates and seasonal patterns of transmission.
The researchers looked at valley fever cases that occurred in 17 California counties between 2000 and 2021 and noted that exposure to the bacteria was highest from July to September and lowest from February to April, based on when cases increased in the weeks following exposure.
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“California has distinct dry (April–October) and wet (November–March) seasons each year, and our results indicate that seasonal peaks in coccidioidomycosis occur most frequently at the end of the dry season. Unusually wet weather during the preceding rainy season and unusually dry weather during the contemporaneous dry season are associated with more pronounced seasonal peaks in incidence,” the researchers wrote.
The study said the findings could help inform public health messaging by explaining “when to avoid particularly dusty environments or activities that generate dust, and when to use dust-suppression techniques, such as wetting the soil before disturbing, if exposure to dust is unavoidable. People can use N95 masks to prevent inhaling fungal spores.
