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What is it?
Blastomycosis is an infection caused by a fungus, Blastomyces dermatiditis. Blastomycosis affects the lungs or skin. Pneumonia caused by the spores may present with fever, chills, cough, sore chest, weight loss, aches and fatigue. Skin infections caused by the spores may begin with lesions on the face or extremities, starting out as painless red pimples progressing to crusty or open wounds. Weight loss, fever and fatigue can also accompany these skin lesions.

Why is it a concern in Northwestern Ontario?
The landscape in this area supports growth of B. dermatiditis. This fungus can be found anywhere, but it is more common in areas of acidic, moist soil such as areas where there are fallen trees that are rotting. Kenora District accounted for 43% of Ontario hospitalizations over the past 5 years where blastomycosis was the main cause.

Why do I need to know about it?
Spores can get into your body through inhalation or through cuts in your skin. Some people who come into contact with the fungus will not get sick at all, but others may become severely ill. Pets become infected more often because their faces are close to the ground. People whose immune systems are compromised are more likely to become severely ill.

Why doesn’t someone do something about it?
There is no vaccine against Blastomycosis. There is no environmental control product to eradicate it from the soil. It cannot be seen. A pet or person can become infected in one location, and hundreds of others may be exposed to the same location and not become infected. When illness results, the symptoms usually arise weeks or even months after exposure, so pinpointing the location of exposure is very difficult in many cases.

Although there is no evidence to support use of any specific personal protective equipment (no proof it will definitely protect you), consider wearing work gloves, long pants and sleeves, enclosed footwear, a dust mask and eye protection when performing work that disturbs soil, especially when your face will be near the soil. Changing the amount and length of time you are exposed to soil dust may reduce risk.

Individuals whose immune system is weakened by chronic illness or medications should also consider avoiding exposure to disturbed soil, especially in moist, acidic areas.

Blastomycosis is much more common in Northwestern Ontario than in other parts of Ontario. If you have been outdoors in Northwestern Ontario and develop symptoms as described, or if you
are starting a medication that will lower your immune system, tell your doctor you may have been exposed to the fungus that can cause Blastomycosis.

Information for physicians
Since symptoms can arise long after exposure, it is important when taking history to ask about possible exposure to B. dermatiditis during the past several months, and to test for it. Blastomycosis will not be identified through viral or bacterial testing; specific testing for fungal infection must be requested. Guidance for laboratory testing can be found here by searching “fungal” in the Public Health Laboratory Specimen Collection Guide.

Treatment information can be found here and here