2024 Sees Unprecedented Spike in Valley Fever Infections
San Luis Obispo County has recorded its highest-ever number of Valley fever cases, with 482 infections reported in 2024, nearly double the 244 cases documented in 2023. This figure surpasses the previous record of 445 cases set in 2017. According to the county’s Public Health Department, the sharp rise is consistent with known patterns of the disease, which often surges following drought conditions combined with heavy rainfall.
“This increase is not unexpected,” said Dr. Penny Borenstein, the County Health Officer. “We know Valley fever tends to rise after dry periods followed by substantial rain. We’re actively educating both healthcare providers and the public to recognize symptoms and understand how to lower their risk.” Dr. Borenstein advised anyone experiencing persistent flu-like symptoms such as fever and coughing for several weeks to consult a healthcare professional and request testing for Valley fever.
Understanding the Source and Spread of the Disease
Valley fever, medically known as coccidioidomycosis, is caused by the Coccidioides fungus, which thrives in the soil across San Luis Obispo County, neighboring regions, the Central Valley, and other parts of the southwestern U.S. When the soil is disturbed—by activities such as digging, driving, or strong winds—spores can become airborne and inhaled by people and animals, potentially leading to infection.
The disease affects individuals differently. About 60% of those infected remain asymptomatic and do not require treatment. Another 30–40% may develop flu-like symptoms but typically recover without medical intervention. However, around 1% of symptomatic cases can experience severe complications if the infection spreads beyond the lungs to other parts of the body.
Public health officials link this year’s spike to environmental changes, specifically an increase in fungal growth due to abundant rainfall following a prolonged drought. These climate conditions have created an ideal environment for the fungus to flourish, increasing the likelihood of exposure and infection.
Prevention Tips and Community Awareness
While Valley fever cannot be transmitted from person to person or between animals, both humans and animals—including dogs, cats, and horses—can become infected by inhaling contaminated dust. The County Health Department recommends several practical precautions to help reduce risk.
Residents are urged to avoid dusty environments, especially on windy days. If exposure is unavoidable, health experts suggest using protective gear such as N95 masks and dampening soil before disturbing it to minimize airborne particles. Drivers traveling through dusty or windy areas should keep car windows closed and set the air conditioning system to recirculate.
The Health Department continues to raise awareness in the community and among healthcare providers to promote early diagnosis and prevention. With Valley fever cases reaching historic levels, residents are encouraged to remain vigilant and informed, especially as environmental conditions remain favorable for the spread of the fungus.
