Blastomyces species cause Blastomycosis, a rare fungal infection usually acquired by inhaling the spores of Blastomyces. It is found in wood and soil after contaminated soil is disturbed by activities such as excavation, construction, digging, or wood clearing. It is not spread from person-to-person or from animal-to-person. Blastomycosis occurs most often in people that live in the central and southeastern United States, particularly in the Mississippi and Ohio River valleys and the Great Lakes states.

The time between exposure and when symptoms develop varies widely, ranging from 21 to 100 days. The signs and symptoms of blastomycosis also vary among individuals. About 50% of people infected do not develop any symptoms or disease and the infection is resolved without treatment. However, some patients develop a chronic lung infection and/or the disease can spread to other areas of the body such as skin, bones, genitourinary system, or central nervous system.

Symptoms may include: Fever, Cough, Cough with blood, Shortness of breath, Muscle aches, Bone pain, Back pain, Chest pain, Fatigue, Weight loss and Skin sores (see photo).