Histoplasma is a genus of dimorphic fungi commonly found in bird and bat fecal material. Histoplasma contains a few species, including—H. capsulatum—the causative agent of histoplasmosis; and Histoplasma capsulatum var. farciminosum (old term, Histoplasma farciminosum), causing epizootic lymphangitis in horses.
is a soil-borne, dimorphic fungus
that causes histoplasmosis
a disease of humans, dogs and cats. It is found throughout the world but is most prevalent in the Americas, India and southeastern Asia favoring a warm, moist, and humid climate. It is endemic in certain areas of the United States
, particularly in states bordering the Ohio River
valley, the Missouri River valley, and the lower Mississippi River
. The fungus has been found in poultry
-house litter, caves
, areas harboring bats
and in bird roosts (particularly those of starlings) but even accumulations of household dust or soil-containing houseplants may be potential sources of infection with this fungi. Infection is usually due to inhaling contaminated air.