Histoplasmosis is caused by the soil- dwelling dimorphic fungus Histoplasma capsulatum. Infection typically results from inhalation of aerosolized spores, and symptomatic infections usually involve pulmonary disease, although disseminated or non-pulmonary infections occur. Asymptomatic infections are thought to be common. The geographic distribution is still under investigation, but the Mississippi River valley is known to be an endemic area. Additionally, geographic micro- foci exist inside and outside endemic areas, and are usually associated with soil containing bird or bat guano.
Common activities associated with exposure include farming, exposure to soil enriched with bird or bat guano, remodeling or demolition of old buildings, and clearing trees or brush in which birds have roosted.
A new case definition was implemented in 2017; thus, case counts cannot be compared to previous years. In 2017, there were 36 confirmed and 147 probable cases of histoplasmosis reported. The median age of confirmed and probable cases was 54 years (range, 8 to 85); 118 (65%) were male. Of the 142 cases with race reported, 130 (92%) were white, 8 (6%) were black, 1 (0.7%) was Asian/Pacific Islander, and 3 (2%) reported more than one race. Of the 131 with ethnicity reported, 10 (8%) were Hispanic/Latino.
Seventy-four cases (40%) were hospitalized, and of the 102 whose status was known, 35 (34%) were immunocompromised. Eleven (7%) cases died, and histoplasmosis was the primary cause of death in 4 of those cases.
- For up to date information see>> Histoplasmosis (Histoplasma capsulatum)
- Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2017