Blastomycosis

Clinical Features

Symptomatic fungal infection (50% of cases) usually presents as a flu-like illness with fever, chills, productive cough, myalgia, arthralgia and pleuritic chest pain. Some patients fail to recover and develop chronic pulmonary fungal infection or widespread disseminated fungal infection (affecting the skin, bones, and genitourinary tract). Occasionally affects the meninges.

Etiologic Agent - Blastomyces dermatitidis fungus.

Reservoir -  Moist soil enriched with decomposing organic debris. Endemic in parts of the south-central, south-eastern and mid-western United States. Microfoci in Central and South America and parts of Africa. 

Incidence -  1-2 cases per 100,000 population in areas with endemic disease. 

Sequelae -  Permanent lung damage with chronic disease. Mortality rate is about 5%.

Transmission -  Inhalation of airborne conidia fungus (spores) after disturbance of contaminated soil.

Risk Groups -  Persons in areas with endemic disease with exposures to wooded sites (e.g., farmers, forestry workers, hunters, and campers). 

Surveillance -  Reportable in a few states in areas with endemic disease. No national surveillance exists.

Challenges -  Improving understanding of sources and routes of fungus transmission from the environment. Developing more sensitive and specific tests for fungal diagnosis. 

Used with permission from the Centers for Disease Control
December 2003