Which are the causes of Blastomycosis?

Blastomycosis is an infectious disease caused by the dimorphic fungus Blastomyces dermatitidis or Blastomyces gilchristii, which thrive in moist soil and decaying organic matter. Humans contract Blastomycosis when they inhale airborne fungal spores, usually after disturbing contaminated environmental sites, rather than through person-to-person transmission.

How is Blastomycosis contracted?

The primary cause of Blastomycosis is the inhalation of fungal spores. When soil or wood is disturbed—such as through gardening, construction, or outdoor recreation—the fungus becomes aerosolized. Once inside the lungs, the fungus undergoes a morphological change; it transforms from a mold (the form found in the environment) into a yeast (the form that survives inside the human body). This transition is critical for the development of Blastomycosis, as the yeast form can evade the host's immune system and spread to other organs.

Are there genetic factors linked to Blastomycosis?

Blastomycosis is not a hereditary or genetic disorder. It is an infectious disease, meaning it is caused by an external pathogen rather than an inherited mutation or chromosomal abnormality. While genetic research is currently exploring why some individuals develop severe disseminated Blastomycosis while others remain asymptomatic, there is no known "Blastomycosis gene" that predisposes one to infection.

What are the primary risk factors for infection?

While the cause is the fungus itself, certain factors increase the likelihood of exposure or the severity of the illness. High-risk groups for Blastomycosis include:

• Individuals living in or traveling to the Ohio and Mississippi River valleys, the Great Lakes region, and the St. Lawrence River valley.


• People who engage in frequent outdoor activities near water, such as fishing, hunting, or camping.


• Individuals with underlying immunocompromising conditions, such as HIV/AIDS, or those taking immunosuppressive medications, as they are at a higher risk of the infection becoming systemic.

What is the current state of research?

Researchers are actively studying the virulence factors of Blastomyces to develop better diagnostic tests and potential vaccines. Currently, the etiology of Blastomycosis is well-understood as an environmental infection, but scientists are investigating the host-pathogen interaction to understand why the immune system fails to clear the fungus in some patients.

Next steps

• Consult an infectious disease specialist if you have respiratory symptoms and live in an endemic area.


• Join our community of 27 members at DiseaseMaps.org to share experiences and find support.


• Use protective gear (such as masks) if working in high-risk environments like soil excavation in endemic regions.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment.

References

• CDC: Blastomycosis (Blastomyces) Statistics and Risk Factors.


• NIH GARD: Genetic and Rare Diseases Information Center - Blastomycosis.


• PubMed: Clinical Practice Guidelines for the Management of Blastomycosis (IDSA).