How to protect against Valley Fever

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Keep employees and your company safe from Valley Fever


Valley Fever is an infection caused by inhaling certain fungus spores in the soil; in fact, inhaling less than 10 spores can cause disease. It’s a hazard in western and southwestern states and can result when workers disturb soil these areas, particularly when trenching or excavating. The fungus itself lives less than 12 inches below the surface. Keep reading to learn how to protect against Valley Fever: what it is, and steps you can take to guard your employees against getting infected.

What is Valley Fever?

Valley Fever crops up (no pun intended) throughout the Southwest U.S, predominantly in Arizona and central California. Cases have been reported in California, Washington, Nevada, Utah, Arizona, New Mexico and Texas. It’s most prevalent in industries where employees have direct contact with the land: agriculture, roadwork, excavation and construction. That’s because it’s caused by a microscopic fungus, Coccidioides immitis, which lives in the top two to 12 inches of arid soil. When the ground is disturbed by wind, farming, construction or other movement, these fungal spores are released into the air and can be inhaled, infecting the lungs and other parts of the body via the bloodstream. Open cuts or scrapes can absorb the spores, causing a skin infection.

Many people exposed to the fungus never have symptoms. Others may have flu-like symptoms that typically go away after weeks to months. They typically appear 1-3 weeks after breathing the spores. According to the CDC (Centers for Disease Control and Prevention), symptoms can include

  • Fatigue
  • Cough
  • Fever
  • Shortness of breath
  • Headache
  • Night sweats
  • Muscle aches or joint pain
  • Rash on upper body or legs

UC Davis’ health website says that 60 percent of those exposed don’t develop symptoms – or have minor flu-like symptoms that resolve on their own. It’s not contagious, but incidence is growing: About 150,000 people contract Valley Fever annually.

Related: How to prevent heat illness in outdoor workers 

Clues that Valley Fever may be in the soil

These conditions are more prevalent in finding the fungus:

  • Lots of animal burrows
  • Old (prehistoric) Native American campsites
  • Areas with sparse vegetation
  • Areas adjacent to arroyos
  • Packrat middens
  • Upper 12 inches of undisturbed soil
  • Sandy, well-aerated soil with high water holding capacity
Related: Workplace Safety Incentives: Stop Accidents Before They Start

Who is most susceptible?

The infection is most common among older adults, particularly those ages 60 and older. People who have recently moved to an area where the disease naturally occurs are also at higher risk for infection.

According to the CDC, other high-risk groups include:

  • African-Americans
  • Filipinos
  • Diabetics
  • Women in their 3rd trimester of pregnancy
  • People with weak immune systems, including those with an organ transplant or who have HIV/AIDS, or take medications such as corticosteroids or TNF-inhibitors
Related: Best practices for reporting workplace incidents

Prevention steps to avoid Valley Fever

We’ve compiled the following steps from the CDC and California’s Dept. of Industrial Relations:

  • Determine if your worksite is in an endemic area.
  • Use water, appropriate soil stabilizers, and/or re-vegetation to reduce airborne dust.
  • Stabilize all spoils piles by tarping or other methods.
  • Use non-susceptible workers.
  • Suspend work during heavy winds.
  • Try to avoid areas with a lot of dust like construction or excavation sites. If you can’t avoid these areas, wear an N95 respirator that will completely seal around your face and prevent particles 2-4 micrometers in size from passing through. Normal paper masks or bandanas will not offer protection since the spores are microscopic.
  • Keep employees indoors during dust storms and close windows.
  • Use air filtration measures indoors.
  • Identify a health care provider for occupational injuries and illnesses who is knowledgeable about the diagnosis and treatment of Valley Fever. Offer preventive antifungal medication if your healthcare provider recommends it.
  • Use machinery and vehicles with enclosed cabs with air conditioning.
  • Clean skin injuries well with soap and water to reduce the chances of developing a skin infection, especially if the wound was exposed to dirt or dust.
  • Clean tools, equipment, and vehicles before transporting offsite.
  • Protect workers’ clothing if it is likely to be heavily contaminated with dust; provide coveralls, changing rooms and showers where possible.
  • Train workers and supervisors about the risk of Valley Fever, work activities that may increase the risk, and measures used onsite to reduce exposure. Also train on how to recognize Valley Fever symptoms.
  • Encourage workers to report Valley Fever symptoms promptly to a supervisor. Not associating these symptoms with workplace exposures can lead to a delay in appropriate diagnosis and treatment.

This article originally appeared in the Arrowhead Tribal blog. It has been updated and modified to better fit the needs of ACM’s workers’ compensation clients.