Blastomycosis

 

What is blastomycosis?

Blastomycosis is an infection caused by a fungus that lives naturally outdoors. The fungus is found in soil and in decaying plants, like wet leaves and rotting wood. In some parts of Canada, including Algoma, this fungus is part of the natural environment. This means people can come into contact with it while living, working, or spending time outside.

People can get blastomycosis by breathing in tiny spores from the environment. These spores are too small to see. Blastomycosis is not spread from person to person, and it is not spread from animals to people.

 

Who is at risk?

Anyone can get blastomycosis, but the chance of getting sick is low. Half of those infected with the fungus will not become ill, although people with certain health conditions may have more severe illness.

People may have a higher chance of coming into contact with the fungus if they spend time outdoors, including:

• Farmers, construction workers, forestry workers
• Hunters, campers, and people who spend lots of time outside

It is not possible to completely avoid the spores because they can be found in many outdoor areas.

 

Is blastomycosis infection common in Algoma?

Blastomycosis is rare, and the overall risk to people in Algoma remains low.

Algoma Public Health tracks cases each year.

In Algoma:

• 2021: 2 cases
• 2022: 1 case
• 2023: 9 cases
• 2024: 7 cases
• 2025: 5 cases
  
  

The number of cases can change from year to year. The increase in recent years is most likely because people are being tested more frequently due to increased healthcare provider awareness of blastomycosis. APH continues to routinely remind healthcare providers to help prevent missed infections.

Every case of blastomycosis is investigated by Algoma Public Health. Right now, investigations in Algoma have not found one clear source or pattern of exposure (for example, one location, job, or shared activity).

Why is blastomycosis hard to prevent?

 

• There is no vaccine to prevent blastomycosis
• There is no reliable environmental testing that can predict risk
• There is no practical way to eliminate contact with the fungus from nature

The most effective way to reduce serious illness is appropriate testing, diagnosis, and treatment from a health care provider when needed.

What are the symptoms?

Blastomycosis most often affects the lungs. Symptoms can start weeks or even months after breathing in the spores. Symptoms may look like other common illnesses.

 

Symptoms may include:

• Cough
• Fever
• Chills
• Shortness of breath

 

When should I seek medical care?

Seek medical care if your symptoms:

• are not getting better, or
• are getting worse, especially if you have a cough that won’t go away or trouble breathing

If you are concerned, contact your health care provider or go to your local emergency department.