Prevent Fungal Diseases in the Workplace

As part of Fungal Disease Awareness Week, we are highlighting fungal diseases that can affect workers. Coccidioidomycosis (Valley fever), blastomycosis, and histoplasmosis are fungal diseases caused by fungi that live in the environment in certain regions. Infections are caused by breathing in fungal spores that get into the air. Some jobs and work activities that disturb soil in areas where the fungi live can release fungal spores into the air and put workers at higher risk. Employers and workers can take steps to reduce risk and prevent workplace exposures to fungal diseases.

Fungal diseases to watch out for

Coccidioidomycosis, or Valley fever, is an infection caused by a fungus called Coccidioides. These fungi live in the soil and are found in the southwestern and some parts of pacific northwestern United States.

Blastomycosis is an infection from a fungus called Blastomyces. Blastomyces mainly lives in the midwestern, south-central, and southeastern states. It is most common in the eastern United States. The fungus lives in the environment in moist soil and decomposing plant matter like wood and leaves.

Histoplasmosis is an infection from a fungus called Histoplasma. Histoplasma mainly lives in soil in the central and eastern United States. However, it can likely live in other parts of the country as well, especially if the environmental conditions (e.g. soil pH) are highly suitable. It grows especially well in places containing large amounts of bird or bat droppings.

Symptoms

Coccidioidomycosis, blastomycosis, and histoplasmosis often present as community-acquired pneumonia in primary and urgent care settings.

Some of the symptoms of these infections include:

• Fever
• Cough
• Headache
• Muscle aches and pain in joints, back, chest, or ribs
• Fatigue (extreme tiredness)

Work activities that might increase your risk

Some outdoor activities can stir more spores into the air and increase risk for infection. In general, workers in areas where these fungi live who are exposed to dust from disturbed soil are at a higher risk.

Coccidiomycosis outbreaks have been recently reported among wildland firefighters and workers constructing solar farms in areas where Coccidioides is present in the environment. In addition, you may have a higher chance of getting coccidioidomycosis if you work in:

• Agriculture
• Archeology
• Construction
• Geology
• Military
• Mining, gas, and oil extraction

An outbreak of blastomycosis was reported among workers at a paper mill in Michigan in 2023. In areas where Blastomyces is present in the environment, you may have a higher chance of getting blastomycosis if you work in:

• Construction and excavation
• Forestry work
• Other settings that disturb soil and plant matter, particularly near rivers or waterways

Histoplasmosis outbreaks have been described among bridge, construction, and prison workers in areas where Histoplasma is present in the environment. In addition to these occupations, you may have a higher chance of getting histoplasmosis if you work in:

• Agriculture and forestry
• Caves
• Construction and demolition
• Landscaping or tree removal
• Mining, quarrying, and oil and gas extraction
• Occupations or industries exposed to bird or bat droppings
• Occupations or industries that disrupt the environment (soil or plant matter disruption)

Employers: Take steps to protect workers

In general, employers should:

• Develop a site safety plan to minimize workplace exposures
• Train workers so they understand the potential risks and how to protect themselves
• Provide personal protective equipment (PPE), including respiratory protection, and associated training to workers
• Encourage workers with workplace exposures to seek a medical evaluation with a healthcare provider
• Make workers aware that these fungal diseases are often misdiagnosed, especially as community-acquired pneumonia, and they should tell their healthcare provider about possible exposures
• Reduce or eliminate dust (spray water or use other dust suppression techniques)
• Safely dispose of any material that might be contaminated while following state and local requirements
• Post health risk warnings in areas known or suspected to be contaminated with fungi

Workers: Take steps to reduce your risk

It is important for workers to understand potential hazards related to their work and how to protect themselves. People who have weakened immune systems should consider avoiding activities that involve disrupting soil. In areas where these fungi are common in the air, it may not be possible to avoid exposure.

Steps for reducing your risk for coccidioidomycosis 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

Some ways to help reduce risk of blastomycosis include:

• Stay inside in windy, dusty conditions
• Avoid activities that stir up or increase contact with dirt
• Wear long sleeve and pants when spending time in the woods

Steps to reduce risk of histoplasmosis include:

• Prevent the accumulation of bird or bat droppings in the first place by excluding bats and birds from buildings
• Eliminate or reduce dust if you must remove droppings or if you are doing construction, excavation, or demolition in areas where Histoplasma is present in the environment (for example, spray water or use other dust suppression techniques)

Wearing a fit tested NIOSH Approved® respirator may protect against all three infections during high-risk activities.

If you work in areas where these fungi live in the environment and develop symptoms, talk to your healthcare provider about the possibility of a fungal infection and potential workplace exposure.

Healthcare providers: Consider patients’ workplace exposures

Coccidioidomycosis, blastomycosis, and histoplasmosis are often misdiagnosed as community-acquired pneumonia or diagnosed late, leading to potentially life-threatening treatment delays. Early diagnosis and prescription antifungals can prevent or treat serious infections. If you treat patients in an area where these fungi are endemic, consider asking patients about their occupation or potential exposures and testing for fungal infection. Clinicians can use these algorithms to guide diagnostic and treatment decisions.

Resources

• Fungal Disease Awareness Week
• General information: Valley Fever (Coccidioidomycosis), Blastomycosis, Histoplasmosis
• Work-related information:
  • Valley Fever Prevention for Workers
  • Histoplasmosis and Work
  • Histoplasmosis Fact Sheet for Workers
  • Histoplasmosis Fact Sheet for Employers

NIOSH Approved® is a certification mark of the U.S. Department of Health and Human Services (HHS) registered in the United States and several international jurisdictions.

Emily Kirby, BPH, is a Health Communication Specialist in the Office of Communication and Research to Practice at the National Institute for Occupational Safety and Health

Marie de Perio, MD, is the Associate Director for Science at the National Institute for Occupational Safety and Health

Mitsuru Toda, PhD, MS, is an epidemiologist in the Mycotic Diseases Branch at the National Center for Emerging and Zoonotic Infectious Diseases

Samantha Williams, MPH, is an epidemiologist in the Mycotic Diseases Branch at the National Center for Emerging and Zoonotic Infectious Diseases

Ian Hennessee, PhD, MPH, is an epidemiologist in the Mycotic Diseases Branch at the National Center for Emerging and Zoonotic Infectious Diseases