About Histoplasmosis and Work

Overview

Histoplasmosis is an infection caused by a fungus called Histoplasma. Anyone who works with or near material contaminated with Histoplasma can develop histoplasmosis.

The fungus lives in the environment, particularly in soil that contains large amounts of bird or bat droppings. People can get histoplasmosis after breathing in the microscopic fungal spores (also known as conidia) from the air.

Most people exposed to Histoplasma never have symptoms. For people who do get sick, the severity of histoplasmosis varies widely. The severity depends on:

• The amount and length of the exposure.
• If the person is at higher risk for developing the severe forms.

Symptoms of histoplasmosis usually appear between 3 and 17 days after a person breathes in the fungal spores. Common symptoms include fever, cough, and fatigue.

What to do

What to do if you are exposed at your workplace

If you think you've been exposed to Histoplasma at work, you should contact:

• Your crew leader or supervisor.
• Your occupational health or risk management department.

If your workplace does not have these services, you should contact your local city, county, or state health department. We do not know if antifungal medication (prophylaxis) can prevent histoplasmosis after a workplace exposure. However, it can be considered for high-risk exposures.

For more information about laboratory exposures to Histoplasma, please see Safety guidelines for laboratory workers who handle Histoplasma.

What to do if you are sick

If you think you have histoplasmosis after working in an area where Histoplasma is common:

• Report your symptoms to your crew leader or supervisor.
• Visit a healthcare provider, if needed.
• Tell them you work in an area where Histoplasma is common.
• Ask to be tested for histoplasmosis.

People at increased risk

Activities associated with histoplasmosis

Environmental disruption of Histoplasma habitats is often a key factor associated with histoplasmosis outbreaks.1 It is also associated with isolated cases,2 although to a lesser extent. These activities include:

• Disturbance of large accumulations of bird or bat droppings.A
• Soil disruption (digging or excavation).
• Plant matter disruption (handling trees or landscaping).
• Demolition, construction, or renovation.
• Working in caves.

Jobs associated with histoplasmosis

In areas where Histoplasma is common, workers in some industries may be at higher risk for histoplasmosis:

• Construction, demolition, and extraction occupations.
• Agriculture and forestry industries.

People who are also at risk include:

• Workers in occupations or industries exposed to bird or bat droppings.
• Those involved with activities that disrupt the environment.

Most of what we know about jobs that may be related to a higher chance of getting sick comes from outbreak investigations. Approximately one-third of histoplasmosis outbreaks in the United States are work-related.1 However, outbreak-related histoplasmosis cases represent only a small fraction of overall known cases (about 5%).2 Examples of people affected by work-related histoplasmosis outbreaks include:1

• Bridge workers.
• Construction or demolition workers.
• Farmers.
• Landscapers or tree removal workers.
• Microbiology laboratory workers.

Histoplasmosis outbreaks have also affected people who were exposed in the workplace but not directly involved in activities that initiated the outbreak. For example, outbreaks affecting office building workers after construction or renovation.1

Resources

Histoplasmosis Fact Sheet for Workers

Histoplasmosis Fact Sheet for Employers

Minnesota Department of Health: Histoplasmosis (Histoplasma capsulatum)

Wisconsin Department of Health Services: Histoplasmosis Fact Sheet

Occupational Histoplasmosis: Epidemiology and Prevention Measures