Source: XL Group, Construction Insider, March 2014
Introduction
The fungus that causes Valley Fever (coccidioidomycosis) is a found in the soil of dry, low rainfall areas. It is endemic (native and common) in many areas of the southwestern United States (See Figure A. below), Mexico, Central and South America. Valley Fever is a common cause of pneumonia in endemic areas. At least 30% – 60% of people who live in an endemic region are exposed to the fungus at some point during their lives. In most people the infection will go away on its own, but for people who develop severe infections or chronic pneumonia, medical treatment is necessary. Anyone can get valley fever, but people who live in California, New Mexico, and Arizona are at increased risk (see Figure A). Certain groups of people are at higher risk of developing severe respiratory problems. It is difficult to avoid exposure to the Coccidioides i. fungus, but people who are at higher risk should try to avoid  breathing in large amounts of dust if they are in endemic areas.
Valley Fever is a potential source of worker’s comp claims, especially in Arizona and

California. The main source of exposure to Valley Fever on construction sites is disturbing the soils (e.g. grading cut/fill, drilling piers, etc.) but personnel can be exposed to the fungus during high wind events or from fungal spores transported
on dust from adjacent sites, e.g. agricultural activities.
Most people who are exposed to the fungus do not develop symptoms, or have very mild flu-like symptoms that go away on their own. Some people may develop a more severe infection, especially those who have a weakened immune system, are of African-American or Filipino descent or are pregnant in their third trimester.
Valley Fever Symptoms
Common symptoms of coccidioidomycosis include:

• Fever
• Cough
• Headache
• Rash on the upper trunk or extremities
• Muscle aches and joint pain in the knees or ankles

Symptoms of advanced coccidioidomycosis include:

• Skin lesions
• Chronic pneumonia
• Meningitis
• Bone or joint infection

Symptoms may appear between 1 and 3 weeks after exposure to the fungus. Some patients have reported having symptoms for 6 months or longer, especially if the infection is not diagnosed right away. If symptoms last for more than a week, it is recommended to contact a healthcare provider.
Treatment of Valley Fever
In many cases, treatment for coccidioidomycosis is not necessary, as symptoms can resolve on their own. Many healthcare providers still prefer to prescribe antifungal medications, such as fluconazole, to prevent a more severe infection from developing. It is especially important for people at risk for severe disease, such as people infected with HIV or those with weakened immune systems, to receive treatment as quickly as possible. It is extremely important for people with severe infections to be treated with antifungal medications because advanced coccidioidomycosis can be fatal if not treated.
Controlling/Monitoring Potential Exposures
The first step to protect personnel and avoid potential exposures is to have everyone on the project trained in the hazards related to Valley Fever, and the steps required to mitigate the hazards. This starts with a notification to project personnel of the hazard during orientation. Contractors using this approach, including the steps outlined below, have recently shared their process with Cal OSHA consultation, which has not offered any additions.

• Train the workers in the hazards of Valley Fever during orientation as part of the Hazard Communication portion of the presentation. Training should cover routes of entry, voluntary use of respiratory protection, hand washing, etc.
• Hire an Industrial Hygienist to collect dust samples for laboratory analysis of the Coccidioides i. fungus early in the project, and ensure the costs for this are built into the bid. Note: Testing for the fungus is difficult even using quantitative industrial hygiene sampling techniques, since one could take a sample on one plot and not find fungus, but an area in close proximity to the first may contain the fungus.
• Hand washing stations should be provided at mobile office trailers and/or field locales.
• Frequently water down the soil where workers are working. For “haul roads” used frequently on large projects use soil glue or liquid calcium chloride (CaCl) application to minimize dust generation. The area surrounding a project such as “lay down” areas, parking lots, etc. may also be sprayed or treated to reduce or eliminate the risk.  However, this may be cost-prohibitive.
• Ensure heavy equipment (graders, skid-steers) have enclosed cabs with HEPA air filtration, whenever possible.
• NIOSH rated N95 respirators should be made available to personnel on a voluntary basis with the OSHA required training (29 CFR 1910.134) for times when airborne dust is an issue, e.g. a farmer plowing on an adjacent plot or public traffic on a road creates the dust and a worker wants to avoid possible exposure.
• Some contractors run a Safety Perception Survey at the project monthly Safety Meeting to determine if workers are satisfied with the steps in place.
• Train project management to be aware for the symptoms of Valley Fever.
• All of these protocols work when the winds are low, but be prepared for Wind/Dust Storms. Contractors have sent workers home due to high winds.
• Project trailers can be equipped with HEPA filters to screen out the spores if present.
• From a general liability (third-party) perspective, contractors working near or adjacent to existing structures, especially health care facilities, should consider working with the facilities department and/or infection control staff to address the potential for spores entering buildings. Risk mitigation measures for operating structures might include protecting air intakes and/or increasing air filter changes to upgrading to HEPA filtration. Inform building occupants to keep doors and windows closed during construction activities.