Key points
- Coccidioidomycosis or Valley Fever is an infectious disease in parts of the United States.
- It is caused by breathing fungal spores.
- Certain jobs and work activities put workers at risk for the disease.
- It is important to take special measures to prevent exposure.
Where it's found
Coccidioidomycosis or Valley Fever is an infectious disease in parts of the United States. It is caused by breathing microscopic spores of the closely related fungal species Coccidioides immitis and C. posadasii. Coccidioides is endemic (native and common) in the southwestern U.S. such as:
- Arizona
- California
- New Mexico
- Nevada
- Texas
Who is at increased risk
Workers in endemic areas exposed to dust from disturbed soil are at a higher risk for Valley Fever.1, 2, 3 Examples include workers in the following fields:
- Agriculture
- Archeology
- Construction
- Geology
- Military
- Firefighting
- Mining, gas, and oil extraction
Preventing exposure
It is important for workers to understand potential hazards related to their work and how to protect themselves. Steps for minimizing exposures include:
- Stop work in dust storms or high winds.
- Minimize hand digging.
- Dig with equipment that has enclosed, air-conditioned, HEPA-filtered cabs.
- Continuously wet soil while digging or moving earth.
- Stay upwind of digging when possible.
The Occupational Safety and Health Administration (OSHA) has a Hazard Communication Standard known as the Right to Know Law. This standard requires employers to provide employees with information about potential work hazards. It also requires employee training on safe work practices, procedures, and protective measures.
Respiratory protection is recommended for those who:
- Dig manually
- Dig using equipment, including enclosed heavy equipment
- Work near earth-moving trucks or equipment in endemic areas
Respirators for employees should be certified by NIOSH and provided with a comprehensive respiratory protection program. This includes:
- Medical clearance for using respirators
- Initial and periodic training and fit testing
- Monitoring for respirator effectiveness
The OSHA Respiratory Protection Standard describes components of a comprehensive respiratory protection program. Employers should assess risks and determine appropriate respiratory protection for dusts and spores. Respirator information can be found on the NIOSH website.
Employers should:
- Wash equipment before it is moved offsite.
- Require workers to change clothing and shoes at the worksite.
- Arrange prompt medical evaluation and treatment of those with possible disease.
The CDC Valley Fever: General information about symptoms, diagnosis, & treatment web page provides further general information about Valley Fever.
- Schmelzer LL, Tabershaw IR [1968]. Exposure factors in occupational coccidioidomycosis. Am J Public Health Nations Health. 1968 Jan;58(1):107-13. PubMed PMID: 5688736; PubMed Central PMCID: PMC1228046.
- Centers for Disease Control and Prevention (CDC) [2013]. Coccidioidomycosis. [https://www.cdc.gov/fungal/diseases/coccidioidomycosis/index.html]. Date accessed: October 3, 2014.
- California Department of Public Health (CDPH) [2014]. Preventing Work-Related Valley Fever Coccidioidomycosis [https://www.cdph.ca.gov/Programs/CCDPHP/DEODC/OHB/Pages/Cocci.aspx]. Date accessed: October 3, 2014.