ABSTRACT
Histoplasmosis is an infectious disease caused by the fungus Histoplasma capsulatum. The fungus lives in soil but also survives by infecting animals and people. Other names for the disease include cave sickness and Ohio Valley disease. There are three varieties of H. capsulatum. One of them (H. capsulatum variety farciminosum) only infects horses, donkeys, and mules; this variety occurs in Africa, the Middle East, and Asia. H. capsulatum variety duboisii only occurs in Africa where it infects humans and baboons. The third variety (H. capsulatum variety capsulatum) has a worldwide distribution and infects humans and numerous animal species (Ajello and Padhye 1994). In this chapter, only the third variety will be discussed; whenever we mention H. capsulatum, we are referring only to H. capsulatum variety capsulatum.
