Valley Fever and Workers’ Compensation

A recent article in the Los Angeles Times noted some interesting statistics concerning the fungus (coccidioides) that causes Valley Fever which is becoming increasingly resistant to drugs because of the spraying of anti-fungal agents on the area crops. The number of Californians diagnosed with Valley Fever rose from fewer than 1500 Californians in 2001 to more than 9,000 in 2023.

When a worker makes a Workers’ Compensation Valley Fever claim, the allegation usually involves exposure to dust in the workplace. The issue is usually litigated because in the San Joaquin Valley area, the dust-loving fungus lives in the soil. In attempting to resolve the issue of causation, the answer is frequently complicated if the worker lives in the endemic San Joaquin Valley area and it is difficult to determine within reasonable medical probability that an exposure to dust particles is work-related. The medical literature notes one study that determined coccidioides spores in the San Joaquin Valley area that had arisen in the San Diego area one hundred miles away with winds blowing spores into the San Joaquin Valley.

Since there is a low threshold of causation, i.e., 1%, a detailed history from the employer regarding any construction sites at the workplace during the period of the alleged exposure and a detailed history of the claimant’s activities of daily living are necessary.

The issue to determine is whether or not the exposure to dust particles at the worksite was in excess of the commonality of dust with coccidioidomycosis spores in the San Joaquin Valley area. A timeline is then needed in order to determine proximate cause from a medical point of view to the onset of the coccidioides infection and how and why the infection may be work-related with an incubation period usually 7 to 21 days.

Available for AME, QME and consultation at Med-Legal Fee Schedule in face-to-face evaluations at Los Angeles, Pomona, Fresno or Televideo. Main Office: (800) 735-1353.