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Blastomycosis

Blastomycosis is a fungal disease. The organism Blastomyces causes blastomycosis. The fungal disease happens when a person breathes in fungal spores from infected soil or other decomposing matter that is disturbed (e.g., digging in dirt, raking leaves).1, 2 Anyone can get blastomycosis if they have been in an area where Blastomyces lives. In Michigan, the fungus lives most often in areas surrounding the Great Lakes.2 Some wooded outdoor activities like forestry work, hunting and camping increase exposure risk.3

Infections typically cause symptoms of pneumonia.1 Infection can be severe in some people, such as those with weakened immune systems.3

Between 2018 and 2022, an average of 25 human cases of blastomycosis were reported each year to the Michigan Department of Health and Human Services (MDHHS).

Blastomycosis data are available on the MiTracking Data Portal

  • Blastomyces is a dimorphic fungus, which means it exists in two different forms, mold and yeast, based on temperature. It grows as a mold at outside air temperatures. The mold develops spores called conidia. Disturbing contaminated soil or decomposing matter can lead to breathing in fungal spores. The spores then transform into a yeast at higher temperatures found inside the human body. The yeast can stay in the lungs or spread through the bloodstream to other parts of the body.2

    For more information, visit Centers for Disease Control and Prevention (CDC) - Blastomycosis Basics.

  • Anyone can get blastomycosis if they have been in an area where Blastomyces lives.2 People from certain racial and ethnic groups may have higher rates of fungal diseases like Blastomyces infection or hospitalization.3

    Some people are at higher risk for severe illness, including3:

    • People who have weakened immune systems, such as those who:
      • Are living with HIV/AIDS.
      • Have had an organ transplant.
      • Are taking medications such as corticosteroids or other immunosuppressive agents.
      • Are pregnant.
    • Infants.
    • Adults aged 55 years and older.

    Is blastomycosis contagious?

    • Person to Person: Blastomycosis does not spread from person to person.4
    • Pets: Pets, often dogs, can get blastomycosis. Blastomycosis does not spread from animals to people besides very rare bite wound infections.3 People and pet blastomycosis symptoms can be similar. Talk to your veterinarian about any pet exposure concerns.

    For more information, visit CDC - Risk Factors for Blastomycosis.

  • About half of the people infected with Blastomyces have symptoms.2 Symptoms begin about three weeks to three months after breathing in fungal spores. Blastomycosis usually affects the lungs causing symptoms of pneumonia.1 Symptoms may include4:

    • Fever.
    • Cough.
    • Night sweats.
    • Muscle and joint pain.
    • Weight loss.
    • Chest pain.
    • Fatigue.
    • Skin lesions.

    The infection can become severe if it spreads. It can spread from the lungs to other parts of the body such as the skin, bones and joints, organs, brain and spinal cord.2

    For more information, visit CDC – Symptoms of Blastomycosis.

  • Completely avoiding the fungus may not be possible in areas where blastomycosis risk is higher. Half of people who breathe in the spores do not get sick.1, 2, 3 People with weakened immune systems should avoid activities that disrupt the soil.

    Some ways to help reduce risk are3:

    • Staying inside in windy, dusty conditions.
    • Avoiding activities that stir up or increase contact with dirt (e.g., yardwork, digging).

    For more information, visit CDC - Risk Factors for Blastomycosis.

  • Healthcare providers can test for blastomycosis by collecting a blood or urine sample. Samples go to a laboratory. Your healthcare provider will order more tests as needed.1

    In pneumonia patients who are not getting better on antibiotics, physicians should rule out blastomycosis or other fungal infections.1

    Most people with blastomycosis symptoms are treated with prescription antifungal medication.1, 3  

    For more information, visit CDC - Fungal Diseases.

  • MiTracking Blastomycosis Indicators

    • Number of human cases of blastomycosis.

    MiTracking Data Can Tell Us

    • The number of human cases of blastomycosis statewide, by year, month, age range, gender and ethnicity.
    • The number of human cases of blastomycosis by year and county of residence.
    • If the number of human cases of blastomycosis is going up or down over time.

    MiTracking Data Cannot Tell Us

    • Where the person was exposed to the Blastomyces organism.
    • Your likelihood of getting blastomycosis.

    Find Out More

    Blastomycosis is reportable in certain states, including Michigan. Physicians and laboratories are required to report suspected cases of blastomycosis to the Michigan Disease Surveillance System or the local health department.

    These data are supplied by MDHHS Emerging Zoonotic Infectious Disease (EZID) Section for MiTracking.

    For additional data information, visit:

    • About These Data (found on the data portal after a query search).
    • Metadata (technical information about the content, quality and context of the data).
  • MDHHS

    Michigan Emerging Diseases

    CDC

    Blastomycosis

    Fungal Diseases

    Health Care Provider Guidance

    Chapman SW, Dismukes WE, Proia LA, et al. Clinical Practice Guidelines for the Management of Blastomycosis: 2008 Update by the Infectious Diseases Society of America. Clinical infectious diseases. 2008;46(12):1801-1812. doi:10.1086/588300

    1. CDC. Blastomycosis. Blastomycosis basics. https://www.cdc.gov/blastomycosis/about/index.html. Accessed September 19, 2024.
    2. CDC. Blastomycosis. What causes Blastomycosis. https://www.cdc.gov/blastomycosis/causes/?CDC_AAref_Val=https://www.cdc.gov/fungal/diseases/blastomycosis/causes.html. Accessed September 19, 2024.
    3. CDC. Risk factors for Blastomycosis. https://www.cdc.gov/blastomycosis/risk-factors/?CDC_AAref_Val=https://www.cdc.gov/fungal/diseases/blastomycosis/risk-prevention.html. Accessed September 19, 2024.
    4. CDC. Clinical overview of Blastomycosis. https://www.cdc.gov/blastomycosis/hcp/clinical-overview/index.html. Accessed September 19, 2024.

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