Valley Fever (Coccidioidomycosis)

Jobs at Risk


shovel in dirt

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Workers in endemic areas exposed to dust from disturbed soil are considered to be at a higher risk for coccidioidomycosis.1, 2, 3 Examples include:

  • Agricultural workers
  • Archeological workers
  • Construction workers
  • Geologists
  • Military personnel/trainees
  • Wildland firefighters
  • Workers in mining, gas, and oil extraction jobs

Outbreaks of work-related coccidioidomycosis have occurred in diverse work settings. These include workers digging trenches4 and cast and crew members at an outdoor television filming event.5 Clusters of infections have also been found among employees and inmates at state prisons located in endemic areas.6, 7

Consideration for Clinical Microbiology Laboratories



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Clinical microbiology laboratories are an important setting for work-related risk of coccidioidomycosis. Cultures of Coccidioides that initially appear as unknown fungal cultures grown from clinical specimens are a risk. Such cultures can form arthroconidia after as few as four days and pose a risk for airborne transmission. All unknown fungal cultures in clinical laboratories should be handled as though they were Coccicioides. They should never be opened outside of a biological safety cabinet appropriate for the organism. This is particularly important for those grown from clinical specimens of patients who have been in endemic areas. Laboratories should have comprehensive prevention plans in place to protect laboratory workers.8


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. []. Date accessed: October 3, 2014.

California Department of Public Health (CDPH) [2014]. Preventing Work-Related Valley Fever Coccidioidomycosis []. Date accessed: October 3, 2014.

Das R, McNary J, Fitzsimmons K, Dobraca D, Cummings K, Mohle-Boetani J, Wheeler C, McDowell A, Iossifova Y, Bailey R, Kreiss K, Materna B [2012]. Occupational coccidioidomycosis in California: outbreak investigation, respirator recommendations, and surveillance findings. J Occup Environ Med. 2012 May;54(5):564-71. doi: 10.1097/JOM.0b013e3182480556. PubMed PMID: 22504958.

Wilken JA, Marquez P, Terashita D, McNary J, Windham G, Materna B; Centers for Disease Control and Prevention (CDC) [2014]. Coccidioidomycosis among cast and crew members at an outdoor television filming event–California, 2012. MMWR Morb Mortal Wkly Rep. 63(15):321-4. PubMed PMID: 24739339.

Pappagianis DCoccidioidomycosis Serology Laboratory [2007]. Coccidioidomycosis in California state correctional institutions. Ann N Y Acad Sci. 1111:103-11.

de Perio MA, Burr GA [2014]. Evaluation of Coccidioides exposures and coccidioidomycosis infections among prison employees. Health Hazard Evaluation Program Report No. 2013-0113-3198, January 2014. []. Date accessed: October 5, 2014.

Stevens DA, Clemons KV, Levine HB, Pappagianis D, Baron EJ, Hamilton JR, Deresinski SC, Johnson N [2009]. Expert opinion: what to do when there is Coccidioides exposure in a laboratory. Clin Infect Dis. Sep 15;49(6):919-23. doi: 10.1086/605441. PubMed PMID: 19663562.