Audit, Compliance and Risk Blog

Valley Fever Endemic in Central California

Posted by STP Editorial Team on Thu, Jul 23, 2015 fever is an illness that usually affects the lungs and is caused by the microscopic fungus known as Coccidiodes immitis, which lives in the top two to twelve inches of soil. While the fungal spores may be present in soils throughout California, they are endemic in the Central Valley counties of Fresno, Kern, Kings, Madera, Merced, San Luis Obispo, and Tulare.

Work activity that disturbs the soil, such as digging, driving, and grading or other earth moving operations, can cause the fungal spores to become airborne and potentially inhaled by workers. All workers on sites where the fungus is present, and who are exposed to dusty conditions and wind-blown dusts, are at increased risk of becoming infected. Occupations at highest risk include, but are not limited to, the following:

  • Construction workers and other workers on construction sites (including road building and excavation crews) 

  • Archeologists

  • Geologists

  • Wildland firefighters

  • Military personnel

  • Workers in mining, quarrying, gas and oil extraction jobs

  • Agricultural workers (although cultivated and irrigated soil may be less likely to contain the fungus than undisturbed soils).

If you work in high risk occupations in areas considered endemic to valley fever and you experience fever, cough, chest pain, chills, night sweats, headache, fatigue, or aching joints, you should seek a healthcare provider as soon as possible. Because the symptoms of valley fever are similar to other more common illnesses, such as colds and flus, diagnosis and treatment is often delayed or even overlooked. For many people valley fever will get better after a few months and without treatment; however, in severe cases this illness can cause chronic pneumonia (lung infection), meningitis (spine and brain infection), or infection in the bones and joints. Valley fever isn’t contagious and after recovering from it most people will not get it again, unless they have a compromised immune system and cannot fight infections. If treatment is required it will typically involve three to six months of an antifungal medication.

At present there is no vaccine to prevent valley fever; however, the following steps can be taken to help limit risk:

  • Determine if your worksite is located in or near an area where the fungus is known exist. 

  • Adopt site plans and work practices that reduce workers’ exposure, including the following: 

    • Minimize the area of soil disturbed.

    • Use water, appropriate soil stabilizers, and/or re-vegetation to reduce airborne dust.

    • Stabilize all refuse piles and surface materials by tarping or other methods. 

    • Provide air conditioned cabs for vehicles that generate heavy dust and ensure workers keep windows and vents closed.

    • Delay work during heavy winds.

    • Ensure any onsite sleeping quarters are located away from sources of dust.

  • When exposure to dust is unavoidable, employers must provide approved respiratory protection.

  • Develop and implement a respiratory protection program in accordance with the California Occupational Safety and Health Administration’s respiratory protection standard. 

  • Take measures to reduce spreading fungal spores offsite, such as cleaning tools, equipment, and vehicles before transporting offsite, and providing coveralls and change rooms (and showers) when worker’s clothing may be heavily contaminated with dust.

  • Identify a healthcare provider for occupational injuries and illnesses who is knowledgeable about the diagnosis and treatment of valley fever. 

  • Train workers and supervisors about the risk of valley fever, which work activities may increase risk, what measures should be used onsite to reduce exposure, and how to recognize symptoms of the illness.

  • Encourage workers to report valley fever symptoms promptly to a supervisor to help ensure appropriate diagnosis and immediate treatment.

Click here for a Hazard Evaluation System and Information Service (HESIS) Fact Sheet on “Preventing Work-Related Coccidioidomycosis (Valley Fever).”

STP has recently published an update to California Training Requirements Compliance Guide and also publishes the following related guides:


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Tags: Employer Best Practices, Health & Safety, Employee Rights, California Legislation, Environmental risks, Environmental, EHS